•    I  iiiiiHiniiiiMi: 

GUIDE  TO  THE  STUDY  OF 

JCHENS 

SCHNEIDER 


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A    GUIDE   TO    THE   STUDY 


OF 


LICHENS 


ALBERT    SCHNEIDER,    M.  D.,    Ph.D. 

Professor  of  Botany,  Materia  Medica  and  Pharmacognosy, 
California  College  of  Pharmacy,  San  Francisco 


With  frontispiece  in  color 

and 

Twenty  plates 


SECOND    EDITION 


BOSTON 

KNIGHT    AND    MILLET 

1904 


Copyright,  1898 
By  Albert  Schneider 


All  rights  reserved 


CONTENTS. 


Preface 
Introduction 


PART  I. 
The  General  Consideration  of  Lichens. 

SECTION  I. 

The  History  of  Lichenology 1 

I.  From    the    Earliest    Time    to    Wallroth  and 

Meyer  (1825) 2 

II.  From  Wallroth  and  Meyer  (1825)  to  the  Close 

of  1896 8 

SECTION  II. 

The  Uses  of  Lichens 16 

I.  The  Function  of  Lichens  in  Nature        ...  17 

II.  The  Economic  Value  of  Lichens        ....  18 

SECTION  III. 

What  are  Lichens? 25 

I.  The  Origin  of  a  Lichen 29 

II.  The   Relation   of    the    Lichens   to   Algjs    and 

Fungi 33 

in.  Lichens  as  Morphological  Units      ....  36 


57G1.' 


•^ 


VI  CONTENTS. 

SECTION  IV. 

The  Morphology  and  Physiology  of  Lichens    ...  39 

I.  The  Thallus 39 

1.  The  Cbdstose  Type 41 

2.  The  Foliose  Type  .       -. 42 

3.  The  Fbuticose  Type 44 

II.  The  Apothecia 45 

1.  The  Fungal  Type 46 

2.  The  Thalline  Type 47 

III.  Accessory  Structures 48 

1.  The  Soredia 48 

2.  The  Cyphell-e 49 

3.  The  Cephalodia 50 

4.  The  Spermagonia 50 

SECTION  V. 

The  Occurrence  and  Distribution  of  Lichens    ...  52 

I.  The  Latitudinal  and  Altitudinal  Distribution 

OF  Lichens 52 

SECTION  VI. 

Lichens  and  the  Naturalist 56 

I.  The  Collection  of  Lichens 56 

II.  The  Study  of  Lichens 63 

III.  The  Pbesebyation  of  Lichens 65 


PART  II. 
The  Systematic  Study  of  Lichens. 

SECTION  I. 
Systems  of  Classification 73 

SECTION  II. 

Keys  to  the  Study  of  Lichens 76 

I.  Artificial  Kky  to  the  More  Important  Genera 

OCCUBBINQ  IN   THE  UNITED   STATES  ...        77 

II.  Natural  Key  to  the  Families 80 


CONTENTS.  VH 

Description  of  Families,  Genera  and  Species  ...  81 

I.  Caliciace^ SI 

II,  Cladoniace^ 87 

III.  Lecideace^ 102 

IV.  Gbaphidace^    .       .       ; 124 

V.  Physciace^ 132 

VI.  Parmeliace^ 144 

VII.  Verrucariageje 169 

VIII.  COLLEMACE^        .          . 179 

IX.  Pannariace^ 184 


Lichens  Imperfecti,  or  False  Lichens 201 

The  Continental  Range  of  the  Lichens  Occurring  in 

THE  United  States 202 

Alphabetical  List  of  the  Genera  and  Species  Repre- 
sented in  the  United  States 204 

General  Index 225 

Plates 235 


PREFACE. 


This  little  work  is  especially  written  and  arranged  for  the 
use  of  amateurs  in  the  study  of  lichens.  By  this  it  is  not  in- 
tended to  convey  the  idea  that  the  presentation  of  the  subject- 
matter  is  unscientific,  incorrect  or  even  out  of  date.  The 
treatment  of  the  subject  is  in  harmony  with  the  most  recent 
results  obtained  by  tlie  leaders  in  the  study  of  lichenology ;  I 
have  simply  endeavored  to  present  these  results  in  such  a  way 
that  they  may  be  comprehended  by  all ;  in  other  words,  an  at- 
tempt has  been  made  to  popularize  our  present  knowledge  of 
lichens.  It  should,  however,  be  kept  clearly  in  mind  that 
only  the  known  facts  or  the  completed  work  of  science  can  be 
popularized.  The  advance-work  of  science,  that  is,  the  work 
whose  aim  it  is  to  make  7}ew  discoveries  or  to  correct  errors,  can 
never  he  popularized ;  as  soon  as  this  is  attempted  it  ceases  to 
be  advance-work.  This  statement  is  intended  for  those  of  the 
laity  who  are  inclined  to  speak  of  scientific  work  as  "  non- 
sense "  or  as  "  a  morbid  taste  for  using  big  words."  It  is  also 
intended  for  the  serious  consideration  of  those  would-be  scien- 
tists who  are  too  anxious  to  "popularize  science."  It  is 
further  hoped  that  this  statement  will  avoid  possible  erro- 
neous conclusions  as  to  the  intended  purpose  of  this  book. 

The  existing  nomenclature-difiiculty  does  not  concern  or 
interest  the  average  student  of  nature.  In  fact,  the  leading 
scientific  specialists  are  themselves  as  yet  wholly  at  sea  as  to 
when  and  where  the  controversy  will  end.  For  this  reason 
the  citation  of  authorities  is  omitted.  Tlie  names  given  are 
well  authenticated,  so  that  those  who  have  the  desire  and  the 


X  PREFACE. 

opportunity  may  enter  into  the  consideration  of  the  synonymy 
and  tlie  nomenclature-controversy. 

The  lichens  described  are.  the  more  common  forms  occur- 
ring in  the  United  States,  those  with  which  tlie  collector  is 
likely  to  come  in  contact.  At  the  close  is  given  a  fairly 
complete  list  of  the  lichens  found  in  the  United  States ;  this 
will  prove  helpful  to  those  who  wish  to  make  exchanges. 
The  artificial  key  is  especially  intended  for  the  use  of  those 
who  are  not  in  possession  of  a  compound  microscope. 

I  take  this  opportunity  to  express  my  grateful  obligations 
to  Dr.  N.  L.  Britton  and  Prof.  Lucian  M.  Underwood,  of 
Columbia  University,  who  placed  at  my  disposal  the  Univer- 
sity collection  of  lichens.  I  am  also  greatly  indebted  to  my 
wife,  who  has  kindly  given  aid  in  correcting  the  manuscript 
and  in  reading  the  proof. 

Albert  Schneider. 

Chicago,  January,  1898. 


PREFACE  TO   SECOND   EDITION. 


The  changes  to  the  second  edition  are  the  addition  of  six 
full-page  half-tone  illustrations  of  typical  representatives  of 
the  three  gi'eat  subdivisions  of  the  lichens ;  namely,  the 
crustose,  foliose,  and  fruticose.  These  veill  be  of  great 
value  to  beginners  in  the  study  of  this  remai'kable  group  of 
plants. 

Since  the  issue  of  the  first  edition  no  important  discov- 
eries have  been  made  in  lichenology,  hence  no  changes  have 
become  necessary  in  the  text. 

I  take  this  opportunity  to  express  my  obligations  to  Miss 
Alice  Eastwood,  of  the  California  Academy  of  Science,  and 
K.  S.  Gray,  Attorney,  San  Francisco,  for  the  loan  of  mate- 
rial, as  well  as  for  assistance  in  collecting  specimens. 

Albert  Schneider. 

San  rRANCisco,  August,  1903. 


INTRODUCTION. 


Lichens  form  a  group  of  plants  which  has  been 
not  so  much  overlooked  and  neglected  as  misunder- 
stood and  abused.  The  term  lichen  is  rather  un- 
familiar, but  not  so  the  term  "  moss,"  by  which  the 
plants  here  referred  to  are  quite  generally  known 
to  layman  as  well  as  to  poet.  And,  indeed,  the  term 
moss  is  justifiable  if  we  trace  it  to  its  Scandinavian 
origin.  All  comparatively  small  thalloid  cryptogams 
—  that  is,  flattened,  stemless  and  flowerless  plants  — 
were  known  as  moss  (most,  mossa,  moos,  mus).  The 
term,  therefore,  included  lichens,  liverworts  and  mosses 
proper.  But  from  the  present  standpoint  of  science 
lichens  are  not  mosses,  as  will  be  made  clear  later ; 
lichens  are  an  independent  group  of  plants  having  no 
genetic  relationship  to  mosses. 

Nor  must  it  be  supposed  for  a  moment  that  lichens 
are  uninteresting  and  insignificant.  With  the  one  ex- 
ception of  marine  algae,  no  plants  present  such  truly 
beautiful  and  artistic  features  to  the  amateur  in  nature- 
study.     No  group  of  plants  is  so  easily  obtainable  or 


Xll  INTRODUCTION. 

lends  itself  so  readily  to  the  critical  examination  of  the 
student  and  to  the  decorative  fancies  of  the  artisan. 
Neither  is  it  necessary  to  enter  a  plea  for  the  kindly 
consideration  of  these  plants  because  they  have  been 
neglected  and  abused.  Lichens  do  not  require  pity : 
they  are  more  than  competent  to  hold  their  own  in 
the  great  struggle  for  existence.  Indeed,  many  of  the 
much  petted  and  much  praised  higher  plants  owe  their 
very  existence  to  the  lichens.  It  is  true,  lichens  can- 
not boast  of  an  exalted  origin  or  noble  ancestry,  but 
they  have  gradually  advanced  in  a  beneficent  life-work, 
so  that  at  present  their  lowly  origin  is  wholly  lost 
sight  of. 

Let  us,  therefore,  obtain  a  better  insight  into  these 
plants,  so  that  we  may  judge  them  more  fairly  and  as- 
sign them  to  their  proper  position  in  the  world  of  life, 
and  duly  credit  them  with  the  grand  work  they  are 
performing.  Let  us  hope  that  no  one,  on  seeing  a 
lichen,  will  say,  "  Oh !  that  is  a  moss,"  or,  "  It's  noth- 
ing ;  it  just  grows  on  trees."  A  lichen  is  as  deserving 
of  recognition  as  the  oak  upon  which  it  grows  or  the 
reindeer  whose  life  it  sustains. 


PART  I 

GENERAL  CONSIDERATION  OF  LICHENS 


THE    HISTORY    OF    LICHENOLOGY. 


SECTION  I. 

THE   HISTORY  OF  LICHENOLOGY. 

The  history  of  lichenology  is  a  remarkable  one.  It 
indicates  that  this  special  science  has  progressed  in  a 
devious  and  interrupted  course.  It  is  only  within  a 
few  years  that  scientists  have  arrived  at  any  compara- 
tive certainty  as  to  the  true  nature  of  these  plants. 
Wonderfully  absurd  opinions  were  entertained  as  to 
their  origin  and  economic  uses.  For  these  reasons  a 
brief  historical  review  is  not  only  interesting  but 
highly  important. 

Historically,  time  is  usually  divided  into  periods  or 
epochs ;  such  divisions  are,  however,  more  or  less 
arbitrary  and  depend  somewhat  upon  the  judgment  of 
the  author.  The  establishment  of  periods  very  greatly 
simplifies  the  presentation  of  an  historical  review.  It 
must,  however,  not  be  supposed  that  the  greater  the 
number  of  epochs  or  periods  the  simpler  the  history; 
generally  the  contrary  is  true. 

The  most  exhaustive  history  of  lichenology  is  that 
by  Krempelhuber,  published  in  the  year  1867.  This 
author  divides  the  history  of  our  science  ii^to  six 
periods,  as  follows  :  1,  from  the  earliest  times  (Theo- 
phrastus)  to  Tournefort  (1694)  ;  2,  from  Tournefort 
to  Micheli  (1729)  ;  3,  from  Micheli  to  Weber  (1779)  ; 
4,  from  Weber   to  Acharius  (1810)  ;  5,  from  Acha- 


Library 
N.  C,  State  Collect 


2  GUIDE   TO   THE    STUDY    OP   LICHENS. 

rius  to  De  Notaris  (1845)  ;  6,  from  De  Notaris  to 
1867.  In  my  *' Text-book  of  General  Lichenology" 
I  have  retained  Krempelhuber's  limitations  of  the 
first  three  periods  ;  the  others  have  been  changed, 
and  the  review  has  been  completed  to  the  beginning 
of  1897.  As  thus  modified,  the  fourth  period  is  from 
Weber  to  Wallroth  and  Meyer  (1825),  the  fifth  from 
Wallroth  and  Meyer  to  Schwendener  (1868),  the 
sixth  from  Schwendener  to  Reinke  (1894),  and  the 
seventh  beginning  with  Reinke.  The  reasons  for 
the  changes  will  become  evident  upon  the  considera- 
tion of  the  historical  review  as  here  given. 

For  the  purposes  of  a  very  brief  review  it  was 
thought  best  to  recognize  two  grand  periods.  Only  a 
few  of  the  more  important  workers  in  lichen ology  will 
be  mentioned.  At  the  present  time  the  publications  on 
lichens  number  many  thousands  ;  to  collect  and  digest 
these  is  the  work  of  years.  The  beginner  will,  how- 
ever, feel  somewhat  relieved  to  learn  that  of  the 
thousands  of  publications  on  lichens  only  a  compara- 
tively few  are  of  any  intrinsic  value  or  add  to  our 
knowledge  of  the  subject. 

I.     FROM    THE    EARLIEST     TIME     TO     WALLROTH     AND 
MEYER    (1825). 

This  may  be  characterized  as  the  period  in  which 
no  real  scientific  study  was  made  of  lichens.  The 
botanical  systematists  of  the  time  devoted  their  at- 
tention to  the  higher  plants,  especially  those  of  real 
or  imaginary  economic  value.  The  lower  plants 
were  quite  generally  neglected,  lichens  in  particular. 


THE    HISTORY    OF    LICHENOLOGT.  6 

In  a  work  ascribed  to  Solomon  a  large  number  of 
higher  plants  are  mentioned  but  not  a  single  crypto- 
gam. The  reason  why  lichens  should  be  especially 
neglected  becomes  apparent  when  we  consider  that 
with  few  exceptions  they  are  not  striking  in  size, 
color  or  form,  nor  do  they  seem  to  possess  any  marked 
useful  or  harmful  properties. 

No  historian  has  been  able  to  give  any  reliable  in- 
formation regarding  the  earliest  knowledge  and  uses 
of  lichens.  Evernia  furfuracea  is  said  to  have  been 
found  with  Egyptian  mummies,  where  it  was  doubtless 
used  as  packing  material.  There  is  no  reason  why 
this  lichen  as  well  as  others  (species  of  JJsnea  in  par- 
ticular) should  not  have  been  used  for  similar  pur- 
poses by  the  ancient  peoples  of  northern  Africa,  Arabia, 
Italy  and  other  countries  in  which  these  plants  occur 
very  plentifully.  Theophrastus  (371-286  B.  C),  a 
pupil  of  Aristotle,  was  perhaps  the  first  writer  who 
left  any  record  of  lichens.  From  his  rather  imperfect 
descriptions  we  are  led  to  believe  that  he  was  more 
or  less  familiar  with  JJsnea  barhata  and  Rocella  tincU 
oria.  The  former  no  doubt  attracted  attention  be- 
cause of  its  beard-like  growth  upon  trees,  oaks  in  par- 
ticular. The  latter  has  been  long  known  on  account 
of  its  coloring  properties.  These  two  lichens  were 
also  mentioned  in  the  works  of  Dioscorides  and 
Pliniiis.  With  these  exceptions,  lichens  received  no 
attention  until  the  sixteenth  century,  when  science, 
art  and  literature  awoke  from  the  paralytic  state  into 
which  it  had  sunk  since  the  first  century.  About  the 
middle   of   the  sixteenth   century,  Ruellius,  Gessner, 


4  GUIDE    TO    THE    STUDY    OF    LICHENS. 

CaBsalpiuus  and  Camerarius,  who  were  among  the 
earliest  commentators  on  the  writings  of  Theophrastus, 
Dioscorides  and  Plinius,  did  little  more  than  to  reiter- 
ate what  was  already  known  of  lichens.  At  the  close 
of  this  century  about  twenty-eight  species  or  forms  of 
lichens  were  described.  The  Scotch  botanist  Morison 
(1683)  described  fifty-six  lichens,  some  of  which  were 
quite  well  figured. 

The  Italian  botanists  were  the  beginners  in  the 
study  of  the  structure  and  growth  of  lichens.  Mal- 
phigi  (1686)  was  the  first  to  call  attention  to  the 
soredia,  which  he  considered  to  be  the  true  seeds  of 
lichens,  since  he  had  observed  that  new  plants  were 
developed  from  them.  Porta  (1591)  gave  some  very 
crude  explanations  of  the  origin  and  growth  of  lichens, 
which  indicated  that  he  had  some  fairly  correct  ideas 
of  the  nature  of  these  plants,  while  Morison,  who 
seemed  to  have  been  an  accurate  observer  otherwise, 
expressed  it  as  his  opinion  that  lichens  were  excremen- 
titious  matter  produced  by  the  soil,  rocks  and  trees. 

At  the  close  of  the  seventeenth  century  about  125 
lichens  were  known  and  described.  Especially  im- 
portant was  the  work  of  Tournefort  (1694-1719). 
This  author  called  special  attention  to  the  apothecia 
and  some  of  the  spores.  His  descriptions  of  the  his- 
tological characters  were  of  necessity  crude,  owing  to 
the  imperfections  of  the  simple  microscopes,  the  com- 
pound microscope  being  as  yet  unknown. 

The  systematic  study  of  lichens  really  began  with 
the  Florentine  botanist  Micheli  (1729).  Heretofore 
all  lichens  had  been  placed  in  the  one  group  "  lichen," 


THE    HISTORY    OF    LICHENOLOGY.  5 

though  some  considered  them  as  "  mosses  "  or  "  fun- 
goid "  mosses.  Micheli  proceeded  to  arrange  all  the 
known  species  or  forms  into  thirty-eight  orders  based 
upon  the  general  macroscopical  characters  and  the  con- 
sistency of  the  thallus.  He  illustrated  the  orders  and 
also  studied  the  apothecia  and  the  spores.  Twelve  years 
later  John  Dillen  issued  his  noteworthy  "  Historia  Mus- 
corum,"  in  which  the  lichens  are  classified  as  mosses. 
His  work  is  well  illustrated,  and  in  many  respects  the 
system  of  classification  is  superior  to  that  of  Micheli. 

After  the  above  botanists  others  exercised  their 
ingenuity  in  establishing  systems  of  lichens.  Some 
authors  classified  them  with  mosses,  while  others 
placed  them  with  fungi.  The  various  groups  were 
quite  universally  based  upon  the  external  appearance 
and  nature  of  the  thallus.  Linne,  "  the  immortal 
Swede"  (1753),  combined  all  lichens  in  one  group  in 
agreement  with  Tournefort.  He,  however,  established 
sub-groups  based  upon  the  characters  of  the  thallus 
as  well  as  upon  those  of  the  apothecia. 

It  will  be  remembered  that  at  first  there  was  a  ten- 
dency to  classify  lichens  as  a  distinct  group  of  plants  ; 
later   to   consider  them   as  mosses  or  even  as  funafi. 

o 

This  doubt  and  uncertainty  continued  to  grow  until 
the  close  of  the  seventeenth  century,  when  the  confu- 
sion reached  its  highest  point.  They  were  not  only 
classed  as  mosses  and  fungi,  but  also  as  algae,  sponges, 
liverworts,  etc.  This  difference  of  opinions  was  due 
to  the  fact  that  the  knowledge  of  the  lower  plants,  of 
lichens  in  particular,  was  very  imperfect.  Linne,  who 
never  pretended  to  be  a  friend  of  the  cryptogams,  des- 


6  GUIDE    TO    THE    STUDY    OP   LICHENS. 

ignated  lichens  as  ^^  rustici  pauperrimi,''  which  might 
well  be  translated  as  "  the  poor  trash  "  of  vegetation. 
This  lack  of  interest  in  the  lower  organisms  was  quite 
universal  and  explains  why  lichens  were  neglected, 
particularly  the  really  insignificant  crustose  forms. 
As  the  result  of  the  combined  efforts  of  the  various 
lichenographers  some  500  species  or  forms  of  lichens 
were  known  at  the  close  of  the  eighteenth  century. 

The  first  investigator  who  made  an  attempt  to  study 
the  morphology  and  physiology  of  lichens  was  J. 
Hedwig  (1784).  Though  his  conclusions  were  in  the 
main  wrong,  yet  his  investigations  served  as  a  stimulus 
and  an  inducement  to  further  study.  This  author, 
was  the  first  to  make  a  special  study  of  the  sperma- 
gonia.  He  also  studied  the  spores  and  soredia. 
He  believed  that  the  spermagonia  were  the  first  to 
develop  and  that  the  apothecia  and  soredia  developed 
upon  these  subsequently.  Furthermore,  the  sper- 
magonia were  looked  upon  as  the  male  reproductive 
organs,  the  soredia  as  the  fertilizing  elements  and 
the  apothecia  with  the  spores  as  the  female  organs. 
A.  P.  De  Candolle  (1798)  made  some  interest- 
ing experiments  as  to  the  manner  in  which  the 
different  lichens  take  up  their  food-supply.  During 
the  same  year  Acharius,  who  is  often  spoken  of 
as  the  "  father  of  lichenology,"  issued  his  "  Prod. 
Lich.  Suec,"  in  which  he  expressed  great  uncertainty 
in  regard  to  the  manner  of  fertilization  and  the  nature 
of  the  reproductive  organs.  He  even  questioned 
whether  lichens  were  plants  and  expressed  a  desire  to 
classify  them  as    polyps.     Georgi    (1779)    made    the 


THE    HISTORY    OF    LICHENOLOGY.  7 

first  chemical  studies  of  lichens.  He  found  that  they 
contain  such  organic  substances  as  oil,  resin  and 
mucus  and  various  inorganic  salts.  In  the  year  1810 
Acharius  issued  his  "  Lichenographia  Universalis," 
which  was  the  most  voluminous  and  complete  work 
on  lichens  yet  issued.  It  is  simply  a  manual  of  lichens 
with  rather  imperfect  descriptions  of  species.  His 
illustrations,  particularly  those  of  the  spores,  are  poor. 
One  would  expect  better  work  from  so  eminent  a  bot- 
anist. He  did  not  make  use  of  the  spore-characters 
in  his  system.  Other  eminent  botanists,  as  Lamarck, 
De  Candolle,  Fries,  F^e  and  Eschweiler,  established 
systems  of  classification  ;  all  of  which  were  artificial 
and  inadequate. 

Some  of  the  leading  botanists  of  the  time  believed 
that  lichens  were  related  to  fungi  as  well  as  to  the 
algae.  Accordingly  Agardh,  Voigt,  Endlicher,  Lind- 
ley,  Reichenbach  and  others  considered  lichens  as  a 
distinct  class  to  be  placed  between  the  algae  and  fungi. 
Sprengel  and  Oken  also  considered  them  as  a  distinct 
class  but  placed  them  between  liverworts  and  algae ; 
De  Candolle  placed  them  between  liverworts  and 
fungi.  Many  other  botanists  still  considered  lichens 
as  a  subordinate  group  belonging  to  various  natural 
classes,  as  algaj,  fungi,  mosses,  etc. 

At  the  beginning  of  the  nineteenth  century  the 
belief  in  spontaneous  generation  was  quite  general. 
Sprengel  and  others  were  convinced  that,  under  favor- 
able circumstances,  lichens  were  evolved  from  decaying 
substances,  or  the  decomposition  of  water.  Agardh 
(1820),    the   eminent   algologist,  stated    that   he  had 


8  GUIDE    TO    THE    STUDY    OF    LICHENS. 

observed  the  development  of  the  lichen  Collema  limO' 
sum  from  the  alga  Nostoc  muscorum  var.  lichenoides. 
A  general  belief  of  that  time  was  that  the  so-called 
"  primal  substance,"  or  "  green  substance  of  Priestley  " 
(perhaps  Protococcus  vulgaris  or  other  unicellular 
alga)  could  develop  into  algae,  lichens,  mosses  and 
other  lower  plants.  Nees  von  Esenback  was  wont  to 
guide  his  pupils  to  the  old  castle  at  Pottenstein  in 
order  to  demonstrate  ad  oculos  how  the  green  sub- 
stance of  Priestley  occurring  on  the  stone  walls  could 
develop  into  a  lichen,  while  if  placed  in  water  it  would 
develop  into  an  alga. 

Thus  we  see  that  during  this  entire  period,  which 
extended  over  two  thousand  years,  scarcely  anything 
more  was  done  than  to  name  and  roughly  describe 
between  500  and  600  species  of  lichens.  The  heated 
discussion,  the  wrangling  and  the  uncertainty  in  regard 
to  the  origin  and  position  of  lichens  was  simply  evi- 
dence of  ignorance  and  not  a  sign  of  profound  knowl- 
edge of  the  subject.  Scarcely  a  ray  of  scientific  light 
had  as  yet  penetrated  the  Stygean  darkness  in  which 
these  highly  interesting  plants  were  enwrapped.  It 
simply  shows  that  scientific  progress,  like  all  progress, 
is  slow  and  its  devious  path  is  strewn  with  thorns  and 
s  tu  mblin  g-blocks . 

II.     FROM     WALLROTH     AND    MEYER     (1825)     TO     THE 
CLOSE     OF     1896. 

This  might  be  designated  as  the  period  of  scientific 
lichenology.  Leading  botanists  now  began  to  study 
the  life-history,  the  morphology,  histology  and  physi- 


THE    HISTORY    OF   LICHENOLOGY.  9 

ology  of  lichens.  It  must,  of  course,  be  cmpliasized 
that  this  was  heretofore  practically  impossible  owing 
to  the  imperfections  of  the  microscope.  The  com- 
pound microscope  was  introduced  at  the  beginning  of 
the  nineteenth  century,  but,  like  all  innovations,  was 
comparatively  imperfect  and  was  looked  upon  with 
disfavor  by  many  scientists  who  should  have  known 
better ;  some  even  going  so  far  as  to  openly  assert 
that  the  compound  microscoj)e  would  never  excel  the 
most  perfect  simple  lenses. 

The  impetus  to  the  scientific  study  of  lichens  was 
given  by  two  German  scientists,  Wallroth  and  Meyer, 
who,  peculiarly  enough,  began  their  work  independently 
but  covered  much  the  same  ground  and  published  their 
results  in  the  same  year  (1825).  Both  made  a  special 
study  of  the  morphology,  growth  and  metamorphosis 
of  the  lichen-thallus.  Wallroth's  style  is  very  in- 
volved. Each  sentence  contains  a  long  series  of 
parenthetical  clauses  often  occupying  nearly  an  octavo 
page.  His  terminology  is  also  peculiar  and  requires  a 
special  study.  On  one  question  the  two  eminent 
writers  were  diametrically  opposed ;  while  Meyer 
believed  in  the  spontaneous  generation  of  lichens, 
Wallroth  did  not,  it  being  his  opinion  that  they  de- 
veloped from  gonidia  and  spores  as  well  as  by  vegeta- 
tive propagation.  Wallroth  gave  a  very  detailed  de- 
scription of  the  structure  and  function  of  the  gonidia, 
soredia  and  apothecia  as  well  as  of  the  tliallus.  Al- 
though this  author  did  most  excellent  work  there  is  no 
evidence  to  show  that  he  made  use  of  the  compound 
microscope  ;  in  some  instances  he  did  not  even  use  the 


10  GUIDE    TO    THE    STUDY    OF    LICHENS. 

simple  lens.  Meyer's  studies  were  perhaps  even  more 
comprehensive  than  those  of  Wallroth.  He  entered 
into  a  careful  investigation  of  the  structure  and  meta- 
morphosis of  the  thallus  and  apothecia,  the  gonidia 
and  spores,  the  growth  and  nutrition  of  lichens  and 
their  relation  to  the  substratum. 

Stitzenberger  (1862)  was  perhaps  the  first  to  em- 
phasize the  importance  of  the  spore-characters  in  the 
classification  of  lichens.  According  to  this  author  it 
is  principally  the  generic  distinctions  which  are  to  be 
based  upon  the  spore-characters.  Lichens  with 
colored  and  colorless  spores  are  not  to  be  included  in 
the  same  genus,  nor  those  whose  spores  differ  in  the 
number  or  direction  of  the  septa,  etc.  According  to 
the  systematist  Kbrber  (1865)  1,051  species  of  lichens 
had  been  collected  in  Germany  and  Switzerland.  Of 
this  number  Korber  described  272  species  as  new. 
Massalonga  (1853)  made  a  careful  study  of  the  struct- 
ure of  crustose  lichens  and  concluded  that  the  spore- 
characters  as  well  as  the  form  and  structure  of  the 
apothecia  and  thallus  should  be  considered  in  the  es- 
tablishment of  genera.  Fries  (1861)  recognized  the 
importance  of  the  spore-characters  but  considered  the 
form  of  the  spermatia  as  of  nearly  equal  significance  ; 
in  this  he  was  seconded  by  other  authors.  The  Eng- 
lish lichenologist  Mudd  (1861)  rightly  objected  to  this 
procedure  because  nothing  was  known  of  the  function 
of  spermagonia  and  also  because  the  spermatia  were 
not  sufficiently  varied  in  form  to  be  of  marked  impor- 
tance in  classification.  Nylander  (1858)  more  than 
any  other  investigator  has  emphasized  the  importance 


THE    HISTORY    OF    LICHENOLOGY.  11 

of  the  spermatial  characters  in  classification.  This 
author,  however,  did  excellent  work  in  the  morphol- 
ogy of  lichens.  He  was  also  the  first  to  point  out  the 
double  affinity  of  lichens ;  on  the  one  hand  they 
showed  a  close  resemblance  to  fungi,  on  the  other  to 
algae.  He  published  a  list  of  all  the  known  lichens, 
which  included  1,348  species,  298  of  which  were  de- 
scribed as  new.  Nasgeli  (1847)  classified  lichens  as 
algae  under  the  group  Lichenaceae  and  placed  them  be- 
tween the  Confervaceae  and  Exococcaceae.  Itzigsohn's 
(1854)  opinions  underwent  great  change  as  regards 
the  spermagonia.  At  first  he  was  inclined  to  look 
upon  them  as  parasitic  fungi,  abnormal  spore-organs, 
apothecia  or  even  parasitic  lichens.  Subsequently  he 
stated  that  they  were  the  antheridia  analogous  to 
those  of  mosses,  of  which  the  spermatia  were  the 
spermatozoa.  Somewhat  later  he  was  inclined  to  be- 
lieve that  the  gonidia  were  the  female  organs  and  the 
spermatia  the  male  organs.  Species  of  the  algae 
Pleurococcus^  Ulothrix,  and  others,  were  supposed  to 
be  free  unfertilized  gonidia.  Tulasne  (1852)  gave  us 
a  very  complete  and  scientific  memoir  on  the  histol- 
ogy of  lichens.  Lindsay  (1856)  wrote  a  most  excel- 
lent popular  treatise  on  British  lichens.  A  little 
later  Schwendener  (1858-1868)  began  his  morpho- 
logical studies  of  lichens  which  were  even  more  com- 
plete than  those  of  Tulasne.  In  1868  Schwendener 
came  to  the  conclusion  that  the  so-called  gonidia  of 
lichens  were  nothing  more  nor  less  than  simple-celled 
algae  and  that  the  spore-bearing  portion  of  the  lichen 
was    a   fungus    living   parasitically   upon    the   algae. 


12  GUIDE    TO    THE    STUDY    OF    LICHENS. 

This  in  a  nutshell  is  the  great  discovery  of  Schwen- 
dener  and  which  has  revolutionized  the  study  of 
lichens.  Reinke  (1873)  pointed  out  that  the  relation 
of  fungus  and  alga  as  it  occurs  in  the  lichen  was  not 
ordinary  parasitism  ;  that  it  indicated  a  relationship  in 
which  both  organisms  were  benefited.  This  relation- 
ship he  designated  consortism.  De  Bary  (1879)  de- 
scribed this  phenomenon  more  fully  and  designated  it 
symbiosis,  that  is  a  "living  together"  for  mutual 
benefit. 

As  a  result  of  Schwendener's  investigations  lichens 
were  considered  as  fungi  and  were  classified  as  such. 
There  was,  however,  great  opposition  to  this  method 
of  classification,  especially  on  the  part  of  the  pure 
systematists.  In  1874  Stahl  made  a  special  study  of 
the  spermagonia  which  led  him  to  conclude  that  the 
spermatia  were  the  male  fertilizing  elements.  Sturgis 
(1890),  an  American  scientist,  seconded  the  conclu- 
sions of  Stahl.  To  Tuckerman  we  owe  most  of  our 
systematic  knowledge  of  the  American  lichens.  His 
descriptions  of  species,  carefully  given,  makes  his 
work  the  first  that  could  be  utilized  by  those  of  ordi- 
nary capabilities.  The  style  of  Leighton's  manual  of 
British  lichens  is  peculiar ;  the  descriptions  of  species 
are  given  in  a  peculiar  mixture  of  English  and  Latin 
which  made  it  necessary  for  him  to  append  an  exten- 
sive glossary  of  terms.  Crombie  (1895),  also  a  Brit- 
ish lichenologist,  retains  the  same  style.  Hue  (1892) 
has  published  a  list  of  lichens  from  which  it  may  be 
concluded  that  about  four  thousand  species  are  known 
at  the  present  time. 


THE    HISTORY    OF    LICHENOLOGY.  13 

Within  comparatively  recent  years  there  have  been 
numerous  investigators  who  have  made  a  special  study 
of  the  relationship  of  fungus  and  alga  as  they  occur  in 
a  lichen.  We  cannot  cite  authors  nor  enter  into  any 
discussion  of  the  results  obtained. 

The  general  conclusions  may  be  summarized  as  fol- 
lows : 

1.  Certain  algae,  mostly  of  the  simpler  Chlorophy- 
ceae  and  Cyanophyceae  have  entered  into  an  intimate 
biological  relationship  with  certain  fungi  mostly  de- 
rived from  the  Ascomycetes  (sac-fungi). 

2.  A  lichen  is  represented  by  a  fungal  portion  and 
an  algal  portion.  The  two  parts  enter  into  a  sym- 
biotic relationship  which  is  of  such  a  nature  that  both 
are  very  materially  benefited.  The  two  organisms 
are  complementary  to  each  other,  one  supplies  what 
the  other  lacks. 

3.  The  fungal  portion  cannot  exist  independently, 
while  the  algal  portion  can. 

4.  The  algal  types  are  fairly  well  known.  They 
are  (1)  Cystococcus  humicola  which  occurs  in  the 
majority  of  lichens  ;  (2)  Pleurococcus  vulgaris ;  (3) 
Exococcus  ;  (4)  Glceocapsa ;  (5)  Chroococcus ;  (6) 
Nostoc ;  (7)  Stigonema;  (8)  Chroolepus ;  (9)  Con- 
fervacece. 

Bornet,  Baranetzky,  Famintzin  and  Woronin  are 
among  those  whose  efforts  have  aided  in  giving  us  a 
more  exact  knowledge  of  lichens.  Jumelle  (1892)  is 
perhaps  the  first  who  has  entered  into  a  careful  study 
of  the  carbon-assimilating  function  of  lichens.  Reinke 
(1894-1896)    after   considerable   study  came    to    the 


14  GUIDE    TO    THE    STUDY    OF    LICHENS. 

conclusion  that  lichens  shotild  be  considered  as  a  dis- 
tinct class.  According  to  this  author  a  lichen  is  as 
much  a  morphological  unit  as  a  fern  or  an  oak.  A 
lichen  is  not  a  fungus  parasitic  upon  algae.  He  has 
shown  that  the  existence  of  the  lichen  is  dependent 
upon  the  relationship  of  the  fungal  portion  and  the 
algal  portion.  Separating  the  two  destroys  the  lichen. 
Lindau  (1895)  objects  to  Reinke's  views  and  agrees 
with  Schwendener.  Darbishire  (1897)  is  a  strong 
supporter  of  Reinke.  He  has  also  made  a  careful 
study  of  the  soredia  (soralia)  as  they  occur  in  the 
Pertusarias.  As  for  myself  I  favor  Reinke's  view  as 
will  be  explained  more  fully  later. 

Thus  concluding  the  historical  review  with  the  be- 
ginning of  the  year  1897,  we  find  the  status  of  our 
knowledge  of  lichens  somewhat  as  follows : 

1.  Schwendener's  theory  of  the  dual  nature  of 
lichens  is  quite  universally  accepted  as  correct.  That 
is,  a  lichen  consists  of  a  fungal  and  an  algal  por- 
tion. 

2.  Reinke's  theory  of  the  autonomy  of  lichens  is 
beginning  to  receive  general  recognition.  According 
to  this  view  a  lichen  is  not  a  fungus  parasitic  upon 
algae.  The  mutual  interdependence  of  the  fungus  and 
alga  is  so  great  that  in  many  instances  neither  can 
exist  alone. 

3.  Lichens  doubtless  form  a  distinct  class  equal  in 
systematic  importance  to  mosses,  fungi,  liverworts, 
etc. 

From  this  historical  review  we  learn  that  lichenol- 
ogy  has  had  a  very  checkered  career  and  that  the  ad- 


THE    HISTORY    OF    LICHENOLOGY.  15 

vance  has  been  very  slow.  Most  of  the  real  scientific 
progress  has  been  made  within  the  past  thirty  or  forty 
years.  Considerable  work  is  yet  to  be  done  before 
our  knowledge  of  lichens  arrives  at  any  considerable 
degree  of  accuracy. 


16  GUIDE   TO    THE    STUDY    OP   LICHENS. 


SECTION   II. 
THE   USES    OF  LICHENS. 

Whatever  exists,  exists  for  a  purpose.  If  it  exists 
for  a  purpose,  it  serves  some  use  in  the  economy  of 
nature.  In  many  instances  this  purpose  or  use  is  not 
apparent  because  not  understood.  If  a  thing  is  decried 
as  useless  it  simply  indicates  that  it  is  not  sufficiently 
understood.  Nature  produces  no  useless  things.  From 
the  standpoint  of  the  optimist,  all  things,  inclusive  of 
those  designated  as  bad  or  harmful,  work  ultimate 
good. 

As  indicated  in  the  historical  review,  lichens  have 
been  unfairly  judged.  They  have  been  looked  upon 
as  vegetable  monstrosities.  One  comparatively  recent 
author  considered  them  as  mosses  which  had  been 
checked  in  their  development.  Linne  looked  upon 
them  as  the  "  beggarly  among  plants."  Others  con- 
sidered them  as  waste  products  of  earth,  rocks  and 
trees.  They  were  quite  generally  considered  as  alto- 
gether insignificant  and  useless,  if  not  harmful.  Even 
poets  were  inclined  to  speak  of  them  disparagingly. 
The  great  part  that  lichens  play  in  the  economy  of 
nature  was  wholly  overlooked.  There  were,  however, 
a  few  who  ascribed  to  these  plants  medicinal  properties 
which  they  do  not  possess.     As  an  article  of  diet  and 


THE    USES    OP    LICHENS.  17 

in  the  dyeing  industry,  lichens  found  a  useful  place 
early  in  the  history  of  civilization. 

I.     THE    P^UNCTION    OF    LICHENS    IN    NATURE. 

The  task  that  lichens  perform  in  the  economy  of 
nature  is  indeed  Herculean  and  out  of  all  proportion 
to  their  size.  They  are  the  hardy  pioneers  preparing 
the  way  for  the  advance  of  the  less  hardy  vegetation. 
Their  hardiness  is  shown  by  their  ability  to  resist 
greater  extremes  of  temperature  than  any  other  plants, 
or  even  animals.  They  have  gained  the  reputation  of 
being  able  to  live  on  nothing  but  air  and  sunlight. 
This  is,  perhaps,  scarcely  true,  but  it  is  a  fact  that  they 
require  less  organic  food  than  other  plants.  In  gen- 
eral, lichens  are  to  be  compared  to  green  chlorophyll- 
bearing  plants,  since  they  take  up  carbon  dioxide  from 
the  air  and  give  off  oxygen.  They  thus  add  their  mite 
toward  keeping  the  air  in  a  suitable  condition  for  the 
respiration  of  higher  animals. 

The  most  important  function  that  lichens  perform 
in  nature  is  the  preparation  of  soil.  Many  of  the 
crustose  lichens  occur  upon  the  hardest  rock,  to  which 
they  are  closely  attached,  forming  dirty  grayish  or 
greenish  patches.  Erroneous  opinions  as  to  the  man- 
ner in  which  lichens  disintegrate  the  rock  are  very 
prevalent.  A  recent  author  puts  it  as  follows  :  "  One 
peculiarity  of  some  lichens  is  the  power  they  have  to 
burrow  into  the  hardest  rocks,  even  flint  and  granite, 
thus  making  for  themselves  homes  (faveoli)."  Other 
authors  make  similar  statements.  Such  statements 
are  wholly  unscientific,  hence  untrue.     No  lichen,  has 


18  GUIDE    TO    THE    STUDY    OF    LICHENS. 

the  power  to  burrow  into  rock  of  any  kind,  not  even 
into  vegetable  tissue ;  such  a  thing  is  physically  im- 
possible. Nevertheless  lichens  disintegrate  the  hardest 
rock,  and  it  is  done  approximately  in  the  following 
manner :  Rock-lichens,  as  well  as  others,  secrete  vari- 
ous acids  which  have  a  solvent  action  upon  the  less 
resisting  rock-particles.  As  a  result  the  rock  crumbles 
and  the  hyphse  of  the  lichen  extend  between  the  loos- 
ened particles.  The  lichen  may  thus  be  almost  entirely 
imbedded  in  the  disintegrated  rock-material ;  the  whole 
mass  being  held  together  and  to  the  unaffected  rock 
the  gelatinous  hyphse.  In  time  the  lichen  dies,  decays 
and  becomes  mingled  with  the  rock-particles,  forming 
a  suitable  substratum  for  the  higher  lichens,  such  as 
the  large  foliose  and  fruticose  forms.  In  turn  these 
also  decay  and  aid  in  forming  a  suitable  soil  for  mosses, 
ferns  and  even  higher  plants  ;  that  is,  death  and  decay 
gives  rise  to  new  life.  Throughout  nature  we  find 
that  those  living  give  up  their  lives  that  others  may 
live.  Lichens  are  the  most  altruistic  of  all  living  or- 
ganisms, since  they  live  wholly  for  the  good  of  others. 
Nearly  all  other  plants  require  at  least  a  substratum 
resulting  from  the  death  and  decay  of  others.  Many 
lichens  live  upon  wholly  inorganic  substrata  and  exert 
their  entire  life-energy  for  the  benefit  of  other  living 
creatures. 

II.     THE    ECONOMIC    VALUE    OF    LICHENS. 

We  shall  here  refer  to  some  of  the  more  important 
uses  to  which  lichens  have  been  put.  Other  special 
uses  will  be  referred  to  in  the  discussion  of  the  species. 


THE    USES    OF    LICHENS.  19 

All  lichens  contain  a  larger  or  smaller  percentage 
of  a  starch-like  substance  known  as  lichenin,  or  lichen- 
starch.  It  has  the  same  chemical  composition  as 
starch  (Cg  H^o  O5)  but  differs  in  that  it  usually  does 
not  give  the  blue  reaction  with  iodine.  It  is  to  this 
substance  that  lichens  owe  their  nutritive  properties. 
From  time  immemorial  the  poor  of  various  countries 
have  made  use  of  lichens  as  an  article  of  diet,  just 
when  it  was  first  so  used  is  impossible  to  determine  ac- 
curately. Excavations  of  prehistoric  cave-dwellings 
''^ermany)  have  revealed  the  presence  of  lichens 
(Cladonia  rangiferind)  among  the  bones  of  various 
animals,  which  would  indicate  that  man  of  that  early 
period  had  already  made  some  economic  use  of  lichens. 
The  "  miraculously  "  supplied  manna  of  the  Israelites 
(Exodus  xvi,  14,  15)  in  the  wilderness  is  supposed  to 
have  been  a  species  of  Lecanora  (Z.  esculentd).  This 
lichen  occurs  very  plentifully  in  the  mountainous  dis- 
tricts of  Tartary,  Algeria  and  other  parts  of  northern 
Africa.  The  plant  occurs  in  small  nodular  masses, 
grows  and  spreads  quite  rapidly  under  favorable  con- 
ditions. These  lichens  are  only  loosely  attached  to 
the  substratum,  so  that  they  are  readily  torn  loose  and 
carried  by  the  wind  into  the  valleys  below,  where  the 
ignorant  and  oftentimes  hungry  peasants  suppose  them 
to  be  bread  rained  from  heaven.  Travellers  in  the  above 
countries  have  reported  several  noteworthy  and  exten- 
sive "rains  of  manna."  The  Kirghiz  Tartars  eat  this 
lichen  under  the  name  of  '-earth-bread." 

Iceland   moss   {Cetraria  islandicn)   h;is   been    most 
extensively  used  as  an  article  of  diet  because  it  con- 


20  GUIDE    TO    THE    STUDY    OF    LICHENS. 

tains  a  high  percentage  of  lichenin.  The  peasantry  of 
Iceland,  Norway  and  Sweden  powder  it  and  mix  it 
with  the  flour  of  various  cereals  and  mashed  potatoes, 
from  which  an  "  uncommonly  palatable  and  healthful 
bread  is  prepared."  A  diet  of  this  lichen  was  also 
said  to  prevent  a  peculiar  form  of  scurvy,  or  elephan- 
tiasis, known  as  "  Iceland  scurvy,"  quite  prevalent  in 
Iceland  and  the  Scandinavian  peninsula. 

Rock-tripe,  a  species  of  Umbilicaria,  has  often  been 
the  means  of  saving  the  lives  of  arctic  explorers,  not- 
ably the  members  of  the  Franklin  expedition,  also  of 
trappers  and  hunters  in  Canada  and  Alaska.  Some 
of  the  companions  of  Franklin  found,  to  their  sorrow, 
that  a  diet  of  this  lichen  produced  a  severe  intestinal 
inflammation,  no  doubt  due  to  the  bitter  principle  it 
contains.  This  bitter  principle  is  more  or  less  present 
in  all  lichens,  and  is  said  to  be  removed  by  repeated 
washings  or  soaking  in  a  solution  of  potash  or  some 
other  alkali.  In  the  northern  countries  of  Europe  a 
common  method  of  preparing  lichens  for  the  table  was 
to  make  a  decoction  in  milk  after  they  had  been  re- 
peatedly washed  in  water.  It  is,  however,  very  difl[i- 
cult  to  remove  the  objectionable  bitter  principle  entirely, 
and  for  this  reason  lichens  were  never  extensively  used 
as  an  article  of  diet,  excepting  in  cases  of  famine.  The 
peasants  of  Norway  and  Sweden  collect  large  quantities 
of  various  lichens  as  fodder  for  their  cattle.  Every 
one  is  familiar  with  reindeer-moss  (^Gladonia  rangi- 
ferind)  as  a  food-supply  for  the  reindeer  of  Lapland. 

Perhaps  the  most  important  and  oldest  use  to  which 
lichens   had   been   put  was   in  the   dyeing   industry. 


THE    USES    OF    LICHENS.  21 

Theophrastus  and  Dioscorides  described  Rocella  tincU 
oria  as  a  "  marine  fungus  growing  upon  rock,  possess- 
ing coloring  properties,"  from  which  it  is  concluded 
that  dye  made  from  the  lichen  was  known  before  that 
time.  It  was  in  use  before  the  time  of  Pliny.  The 
"blue  and  purple"  of  the  Old  Testament  (Ezekiel, 
xxvii,  7)  no  doubt  refers  to  the  coloring  substance 
obtained  from  this  lichen. 

After  the  fall  of  the  Roman  empire  the  knowledge 
of  the  use  of  the  dye  obtained  from  Rocella  seems  to 
have   been  lost.     About  the  year  1300,  Federigo,  a 
Florentine   of   German   parentage,  accidentally  redis- 
covered the  method  of  preparing  and  using  this  dye. 
He  is  said  to  have  achieved  such  great  success  in  his 
commercial  transactions  therewith  that  in   time  he  be- 
came the  head  of  a  distinguished  family,  the  Oricellarii, 
who  were  later  known  as  the  Rucellarii  and  Rucellai. 
From    these   names    are   derived    orseille,    the   name 
given  to  the  coloring  substance,  and  Rocella,  the  group 
of   lichens  from  which   orseille    was    prepared.     For 
more  than  a  century  Italy  supplied  the  market  with 
orseille  derived  mainly  from  lichens  collected  on  the 
islands  of  the  Mediterranean.     After  the  discovery  of 
the  Canary  Islands,  in  1402,  much  of  the  dye  was  ob- 
tained from  those  islands;  still  later  from  the  Cape 
Verde  Islands,  as  well  as  from  other  islands  and  coun- 
tries.    Later  it  was  found  that  species  of  Lecanora, 
Pertusan'a,    Umbilicaria,   Gyrophora,  etc.,  yielded  ex- 
cellent dyes. 

The  method  of  preparing  the  dye  is  quite  compli- 
cated and  many  complex    chemical  reactions  are  in- 


22  GUIDE    TO    THE    STUDY    OF    LICHENS. 

volved.  In  general,  it  may  be  stated  that  the  lichen  is 
pulverized  and  macerated  for  some  time  in  some  alka- 
line solution,  as  lye,  or  ammonia,  whereby  a  beautiful 
purple  color  is  obtained.  Orchill,  cudbear  and  lit- 
mus are  different  names  for  the  same  coloring  sub- 
stance. The  first  is  the  English  preparation  which 
occurs  as  a  rich  purple  paste  ;  the  second  is  the  Scotch 
preparation  which  is  found  in  the  market  as  a  carmine 
or  crimson  powder ;  the  third  is  the  Dutch  prepara- 
tion and  occurs  in  small  oblong  cakes  of  an  indigo- 
blue  color.  Litmus,  as  well  as  the  other  dyes, 
has  the  peculiarity  of  turning  red  in  the  presence  of 
an  acid  and  blue  in  the  presence  of  an  alkali.  The 
litmus-paper  so  extensively  used  in  chemical  labora- 
tories is  ordinary  filter  paper  dipped  into  a  neutral 
solution  of  litmus. 

Later  orseille  was  used  principally  in  dyeing  silken 
goods.  France  more  than  any  other  country  improved 
upon  the  methods  of  extracting  the  dye,  as  well  as  in 
applying  it.  As  to  the  value  of  the  dye  it  may  be 
stated  that  about  the  middle  of  this  century  the 
"  orchella-weed  "  sold  at  prices  ranging  from  $100  to 
more  than  $1,000  per  ton.  The  chief  objection  to  the 
use  of  orseille  is  its  instability,  being  subject  to  fading ; 
furthermore,  the  process  of  dyeing  is  very  apt  to  injure 
the  cloth.    Orseille  is  also  used  by  artists  as  a  pigment. 

In  Sweden  Evernia  vulpina  is  known  as  "  Ulf- 
mossa"  (Wolf's  moss),  because  it  was  said  to  have 
been  used  in  poisoning  wolves.  According  to  Virey, 
the  lichen  is  powdered  and  mixed  with  powdered 
glass,  which  is  sprinkled  upon  meat  exposed  for  wolves 


THE    USES    OF    LICHENS.  23 

to  feed  upon.  The  wolves  eat  of  tliis  and  die.  Accord- 
ing to  Fabricius,  nux  vomica^  and  not  powdered  glass, 
"was  mixed  with  (he  lichen,  which  seems  more  probable. 
Tlie  dog-lichen  {Peltigera  canina)  formed  the  basis 
of  the  noted  "  anti-hydrophobia  powder  "  (pulvis  anti- 
lyssns  or  pulvis  contra  rabiem)  of  the  London  Phar- 
macopoea  (1721  to  1788).  In  the  history  of  the 
Royal  Society  (London)  it  is  recorded  that  several 
mad  dogs  belonging  to  the  Duke  of  York  were  cured 
by  this  powder.  Dr.  Mead  recommends  the  following 
treatment  in  a  case  of  hydrophobia :  "  The  patient  is 
bled  and  ordered  to  take  a  dose  of  the  powder  (equal 
parts  of  the  lichen  and  red  pepper  powdered)  in  warm 
milk  for  four  consecutive  mornings  ;  thereafter  he 
must  take  a  cold  bath  every  morning  for  a  month  and 
for  two  weeks  subsequently  three  times  a  week." 
Dioscorides  recommended  Usnea  harhata,  known  as 
the  "  beard  moss,"  in  certain  diseases  peculiar  to 
women.  Later  it  was  very  highly  prized  as  a  remedy 
for  whooping-cough,  epilepsy  and  as  an  anodyne.  It  also 
formed  the  main  ingredient  in  powders  recommended 
to  promote  the  growth  of  hair.  The  yellow  Physcia 
parietina  was  considered  a  specific  in  jaundice  and 
■was  also  used  as  a  substitute  for  quinine.  During  the 
Napoleonic  wars  (1809-1815)  fevers  of  all  kinds 
raged  in  the  military  hospitals.  Quinine,  which  was 
then  the  popular  remedy  for  fever,  became  very  scarce, 
on  account  of  its  rapid  consumption  and  because  of  the 
commercial  blockade  which  prevented  its  importation. 
Tlie  Austrian  government  therefore  offered  a  prize 
of  five  hundred  ducats  for  the  discovery  of  a  cheap 


24  GUIDE   TO    THE    STUDY   OF    LICHENS. 

and  readily  accessible  substitute  for  quinine.  Sanders, 
who  secured  the  prize  in  part,  proposed  Physcia 
parietina  as  such  a  substitute.  It  proved,  however, 
very  unsatisfactory  and  its  use  was  soon  entirely  dis- 
continued by  physicians. 

From  their  alleged  aptitude  for  imbibing  and 
retaining  odors  and  scents  the  powder  of  several  fruti- 
cose  lichens  formed  the  basis  of  certain  perfumes 
which  were  celebrated  in  the  seventeenth  century. 
The  astringency  of  some  species  rendered  them  ser- 
viceable in  tanning  and  even  in  brewing ;  the  beer  of 
a  certain  Siberian  monastery,  celebrated  for  its  peculiar 
bitterness,  owed  this  to  Sticta  pulmonaria.  French 
and  Scandinavian  chemists  employed  Cetraria  island- 
tea  and  Cladonia  rangiferina  in  the  manufacture  of 
alcohol.  The  method  of  procedure  is  essentially  as 
follows:  The  lichens  are  treated  with  sulphuric  or 
hydrochloric  acid,  which  transforms  the  lichenin  into 
glucose ;  this,  being  allowed  to  ferment,  produces 
alcohol.  Two  pounds  of  the  lichen  furnishes  about 
one  pint  of  alcohol. 

Attempts  were  also  made  to  use  lichens  in  the 
manufacture  of  paper  but  the  results  were  very  unsat- 
isfactory, as  these  plants  contain  no  tenacious  fibres. 
They  are  still  very  extensively  used  in  the  decorative 
work  of  the  taxidermist.  Some  species  furnish  a  gum 
used  in  the  manufacture  of  pasteboard. 

In  conclusion,  it  may  be  stated  that  the  medicinal 
virtues  of  lichens  are  largely  imaginary.  The  only  offi- 
cinal lichen  to-day  is  Cetraria  islandica,  a  decoction  of 
which  is  recommended  as  a  tonic  for  convalescents. 


WHAT    ARE    LICHENS  ?  25 


SECTION   III. 
WHAT  ARE   LICHENS? 

In  order  to  comprehend  the  true  nature  of  lichens 
it  is  necessary  to  have  a  correct  idea  of  their  origin ; 
we  must  have  some  conception  of  their  j^osition  in 
nature,  of  their  relation  to  other  plants.  Lichens  ori- 
ginated in  a  manner  wholly  different  from  any  other 
group  of  plants.  Their  history  of  development  is  most 
remarkable,  and  stands  without  a  parallel  in  the  world 
of  living  things.  In  order  to  make  clear  this  wonder- 
ful origin  and  development  it  is  necessary  to  enter  into 
a  brief  consideration  of  fungi  and  the  lower  algae.  The 
impatient  reader  may  ask,  "What  do  fungi  and  algas 
have  to  do  with  lichens  ?  "  He  will  soon  learn  that 
without  these  plants  lichens  could  not  have  come  into 
existence.     We  shall  begin  the  discussion  with  algae. 

Every  one  is  more  or  less  familiar  with  the  lower 
alga2 ;  they  occur  plentifully  upon  tree-trunks,  fences, 
upon  flower-pots,  walls  and  woodwork  of  greenhouses, 
etc.;  they  form  the  green  scum  on  ponds  and  brooks,  in 
watering-troughs,  in  fact,  in  nearly  all  moist  })laces 
and  in  water  exposed  to  sunlight  and  warmth.  These 
plants  are  very  small,  the  individual  plant  is,  in  fact, 
too  small  to  be  seen  by  the  naked  eye.  Several  hun- 
dred must  become  associated  to  form  a  minute  green 
speck. 


26  GUIDE    TO    THE    STUDY    OF    LICHENS. 

If  we  scrape  off  a  small  fragment  of  the  green  coat- 
ing of  a  tree  or  flower-pot  and  examine  it  under  a 
microscope  we  find  that  it  consists  of  numerous  minute 
globules,  perhaps  five-thousandths  of  an  inch  in  diam- 
eter. Each  globule  is  an  individual  alga  and  is  nothing 
more  or  less  than  a  single  cell.  Not  all  of  the  lower 
algae  are  single-celled  however ;  many  consist  of  chains 
or  filaments  of  cells  or  even  of  a  highly  complex  struct- 
ure. The  algae  with  which  we  are  concerned  are  either 
single-celled  or  form  simple  or  branching  chains  of 
cells.  Their  structure  will  be  more  fully  described 
later. 

Algae  contain  a  green  substance  known  as  chloro- 
phyll. It  is  this  substance  which  enables  the  organism 
to  assimilate  inorganic  food ;  a  function  peculiar  to  all 
chlorophyll-bearing  plants  and  which  distinguishes  them 
from  animals  and  parasitic  plants.  Animals  and  fungi 
can  only  assimilate  the  food-substances  directly  or  in- 
directly prepared  by  the  chlorophyll-bearing  plants. 
This  brief  reference  to  the  algae  will  suffice  for  the 
present.  The  facts  to  be  distinctly  kept  in  mind  are 
that  alg£e  contain  chlorophyll  and  have  the  power  of 
assimilating  inorganic  food-substances  under  the  influ- 
ence of  sunlight.     Now  as  to  the  fungi. 

Every  one  has  seen  toadstool-s,  puff-balls,  mould 
on  bread  and  other  organic  substances  kept  in  moist 
and  rather  dark  places,  rust  on  wheat  and  other  cereals, 
smut  on  corn,  etc.;  all  of  these  are  fungi.  Every  one 
has  heard  of  bacteria  and  is  more  or  less  familiar  with 
the  role  they  play  in  disease ;  some  have  no  doubt 
heard  of  the  importance  of  bacteria  in  the  manufacture 


"WHAT    ARE    LICHENS  ?  27 

of  cheese,  in  tanning,  and  in  tlie  making  of  butter;  all 
are  familiar  with  processes  of  fermentation.  These 
bacteria,  wlietlier  indifferent,  harmful  or  beneficial, 
and  the  producers  of  fermentation,  belong  to  the 
fungi. 

It  is  also  generally  known  that  fungi  are  either 
saprophytic  or  parasitic,  that  is,  they  require  organic 
food  obtained  from  dead  or  living  organisms.  In  this 
they  differ  markedly  from  chlorophyll-bearing  plants, 
as  already  indicated.  Scientists  have  however  deter- 
mined that  fungi  were  originally  chlorophyll-bearing 
and  hence  able  to  assimilate  inorganic  food  ;  in  other 
words,  fungi  are  algae  which  have  lost  their  chlorophyll 
and  the  functions  pertaining  thereto.  How  did  they 
come  to  lose  their  chlorophyll  ?  The  history  of  this 
change  is,  perhaps,  something  as  follows  :  Many  ages 
ago  certain  of  the  algse  accidentally  came  in  contact 
with  higher  plants,  from  which  they  absorbed  some  of 
the  more  soluble  food-substances.  The  association  re- 
duced the  amount  of  work  to  be  done  by  the  chloro- 
phyll of  the  parasite ;  as  the  association  continued  the 
morphological  and  physiological  changes  in  the  alga 
tended  toward  a  more  and  more  marked  parasitism. 
Every  one  is  familiar  with  the  fact  that  inactivity  of 
an  organ  causes  it  to  become  dwarfed  and  more  or  less 
functionless.  Chlorophyll  became  extinct  in  these 
parasitic  algae  simply  because  it  was  functionless :  all 
of  the  organic  food  was  prepared  and  supplied  by  the 
host.  This  change  was  by  no  means  sudden  ;  it  re- 
quired many  ages  to  produce  the  change  from  bright 
green  alga  to  colorless  fungus,  or,  in  other  words,  to 


28  GUIDE    TO    THE    STUDY    OF    LICHENS. 

convert  the  independent  chlorophyll-bearing  organism 
into  a  dependent  chlorophylless  organism. 

The  above  is  in  brief  the  history  of  the  origin  and 
development  of  all  vegetable  parasites.  Even  now  we 
can  find  all  gradations  between  parasitic  states  just 
making  a  beginning,  as,  for  example,  some  species  of 
Nostoc  and  Protococcus,  and  the  most  highly  developed 
parasitism,  as,  for  example,  most  of  the  fungi.  Sapro- 
phytes differ  from  parasites  only  in  that  the  originally 
green,  hence  chlorophyll-bearmg  plants,  became  adapted 
to  live  upon  dead  organic  matter  rather  than  living 
organisms.  It  must  also  be  kept  in  mind,  that  as  par- 
asitism and  saprophytism  progressed  the  resulting 
fungi  underwent  structural  changes  ;  so  that  it  is  in 
many  instances  practically  impossible  to  recognize  the 
resemblance  to  any  living  forms  of  algae.  Scientists 
are,  however,  quite  generally  agreed  that  fungi  are 
derived  from  algae. 

As  a  rule,  fungi  reproduce  their  kind  by  means  of 
very  minute  microscopic  bodies  known  as  spores.  All 
of  the  higher  fungi  may  be  divided  into  two  groups 
according  to  the  manner  in  which  the  spores  are  formed ; 
in  the  one  group  they  are  formed  on  the  ends  of  spe- 
cialized hyphae,  known  as  hasidia,  in  the  other  group 
they  are  formed  within  specialized  hyphee,  known  as 
spore-sacs  (Asci).  The  latter  are  therefore  commonly 
known  as  sao-fungi.  We  have  to  deal  with  the  sac- 
fungi  (Ascomyctes)  only.  There  is,  however,  one 
Southern  lichen  (  Cord)  which  forms  basidio-spores.  It 
is  the  only  exception  occurring  in  the  United  States 
and  is,  furthermore,  of  rare  occurrence.   Keeping,  there- 


WHAT   ARE    LICHENS?  29 

fore,  in  mind,  that  in  the  discussion  of  lichens  we  are 
concerned  with  certain  genera  of  the  lower  algae  be- 
longing to  the  Chlorophyceae  and  the  Cyonophyceae,  and 
a  division  of  the  higher  fungi  known  as  sac-fungi 
(Ascomycetes),  we  shall  now  briefly  ex^Jain  the  phylo- 
genetic  history  of  a  lichen.  The  origin  of  one  lichen  is 
in  all  essential  respects  similar  to  that  of  any  other,  so 
that  one  example  will  suffice  to  make  clear  the  origin 
of  all  lichens. 

I.     THE    ORIGIN    OF    A    LICHEN. 

As  to  the  time  when  the  first  lichen  was  formed 
nothing  definite  is  known.  We  may,  however,  safely 
conclude  that  they  existed  in  the  geological  periods 
along  with  algae  and  fungi.  We  are  certain  that  they 
could  not  have  existed  before  the  development  of  fungi, 
as  explained  above  ;  we  also  know  from  what  has  gone 
before  that  algae  antedate  fungi,  from  which  we  con- 
clude that  lichens  began  their  existence  many  ages 
later  than  the  first  alga?  and  fungi.  From  the  great 
structural  and  functional  specializations  that  lichens 
have  undergone,  we  must  again  conclude  that  they  be- 
gan their  existence  far  back  in  the  geologic  ages,  that 
is,  millions  of  years  ago. 

If  we  select  one  of  the  foliose  Parmelias  as  a  type, 
the  hypothetical  assumption  is  that  its  origin  was  as 
follows  :  A  sac-fungus  (Ascomycete)  evidently  belong- 
ing to  the  genus  Patella,  found  it  diflicult  to  maintain 
a  thrifty  existence  as  a  saprophyte  ;  the  organic  food- 
supply  was  no  longer  adequate  to  keep  up  sufiicient 
energy  to  maintain  a  successful  struggle  for  existence. 


30  GUIDE    TO    THE    STUDY    OF    LICHENS. 

The  many  generations  of  a  life  of  dependent  luxury 
had  greatly  crippled  its  energies;  functionally  it  be- 
came more  and  more  weakened,  until  finally  it  could 
not  even  digest  a  sufficient  quantity  of  the  food  already 
prepared,  or,  in  other  words,  it  no  longer  possessed  suf- 
ficient vitality  to  feed  itself.  In  order  to  regain  its 
lost  vitality  it  must  again  appropriate  a  larger  amount 
and  better  quality  of  food ;  inorganic  food  was  not 
available,  because  it  had  lost  its  chlorophyll.  *If  the 
fungus  could,  however,  prevail  upon  some  chlorophyll- 
bearing  organism  to  prepare  inorganic  food-substances 
for  its  assimilation  the  problem  would  be  solved  ;  that 
is,  it  must  press  into  its  service  some  plant  having 
chlorophyll.  As  already  indicated,  ordinary  parasitism 
with  higher  plants  did  not  suffice:  these  plants  were 
not  sufficiently  adapted  to  its  needs.  The  fungus  was 
therefore  obliged  to  cast  about  for  different  plants, 
such  as  were  specially  suited  to  its  physiological  re- 
quirements. Splendid  opportunities  were  offered  in 
the  numerous  single-celled  algae  (Protococcus  vulgaris), 
known  as  "  green  mould,"  which  everywhere  covered 
trees,  rocks,  etc.  The  fungus  made  the  attempt  and 
entered  into  a  biological  relationship  with  this  alga. 
It  is  highly  probable  that  this  first  relationship  was  of 
a  parasitic  nature  but  the  fungus  soon  found  that  these 
minute  organisms  were  scarcely  able  to  supply  the 
extra  food  materials  demanded  by  the  attaching  para- 
site ;  the  climatic  conditions  were  not  sufficiently  favor- 
able, and,  furthermore,  the  alga  itself  showed  a  slight 
preference  toward  leading  a  parasitic  life,  so  that  the 
fungus  was  considered  as  a  very  undesirable  intruder. 


WHAT    ARE    LICHENS  ?  31 

If  the  organisms  could  in  some  way  form  an  associa- 
tion mutually  beneficial  they  would  both  be  enabled  to 
maintain  the  struggle  for  existence.  This  is  what 
actuall}'- occurred :  the  two  organisms  seem  to  have 
made  an  agreement  to  assist  each  other.  Whether 
this  was  a  truly  altruistic  motive,  or  whether  it 
was  a  case  of  necessity  is  rather  difficult  to  deter- 
mine. It  was  most  likely  a  case  of  necessity  ;  that  is, 
the  mutualistic  association  was  compulsory  in  order 
to  prevent  extinction.  No  matter  which  was  the 
prime  motive,  it  remains  a  fact  that  the  alga  and 
fungus  finally  entered  into  an  association  which  was 
mutually  beneficial.  This  association  is  very  different 
from  parasitism  (antagonistic  symbiosis),  and  is  recog- 
nized by  scientists  as  a  specialized  form  of  mutualistic 
symbiosis,  designated  as  individualism  ;  the  organisms 
which  enter  into  the  formation  of  symbiotic  associations 
are  known  as  symhionts. 

The  relation  of  the  symbionts  under  discussion 
(fungus  and  alga)  was,  in  a  sense,  complementary  :  one 
supplied  what  the  other  lacked ;  there  was  a  harmoni- 
ous and  equable  assignment  of  labor  ;  each  did  that  for 
which  nature  had  best  fitted  it.  In  fact,  we  may  draw 
therefrom  a  wholesome  lesson.  It  should  teach  us  to 
make  that  our  life-work  for  which  we  are  by  nature 
best  fitted  so  as  to  accomplish  a  maximum  of  good 
results. 

As  to  the  division  of  labor  in  the  establishment  of 
the  lichen,  the  principal  function  of  the  fungus  is  to 
supply  protection  ;  that  is,  a  mechanical  function  :  the 
chief  work  of  the  alga  is  to  perform  the  function  of 


32  GUIDE    TO    THE    STUDY    OF    LICHENS. 

assimilation.  The  fungus  gave  protection  to  the  algae 
by  forming  a  suitable  covering  to  prevent  sudden 
evaporation  of  moisture ;  it  also  served  to  conduct 
moisture  and  soluble  food  substances  and  supplied  suit- 
able mechanical  tissues  to  hold  the  plant  firmly  to  the 
substratum  (trees,  soil,  rock,  etc.).  The  alga,  due  to 
its  chlorophyll,  assimilated  the  carbon  dioxide  (COg) 
of  the  air  and  formed  organic  compounds  for  the 
use  of  the  fungus  as  well  as  for  its  own  use.  The 
mutual  adaptations  became  more  and  more  highly 
specialized,  until,  after  many  thousands  and,  perhaps^ 
millions,  of  generations,  a  large  foliose  lichen  was  pro- 
duced, as  one  of  the  higher  Parmelias.  This  is,  in 
brief,  the  probable  history  of  the  j^hylogenesis  of  Par- 
melia.  At  different  periods  other  lower  algae  entered 
into  mutualistic  associations  with  other  sac-fungi.  Each 
prototype  developed  in  different  directions,  producing 
new  species  and  finally,  perhaps,  distinct  genera  of 
lichens.  Lichens  did,  therefore,  not  spring  from  a 
single  ancestral  alga  and  fungus,  they  are  represented 
by  a  poly-ancestry. 

Another  remarkable  thing  is  the  fact  that  the  agree- 
ment formed  by  a  given  alga  and  fungus  was  by  no 
means  permanent ;  after  a  long  phyletic  history  a  given 
lichen  may  have  changed  its  alga,  that  is,  the  partner- 
ship was  dissolved  and  another  compact  entered  with 
a  new  alga.  In  many  instances  a  new  partner  was 
taken  in  and  the  old  was  retained,  so  that  we  find  some 
lichens  with  two  algal  symbionts. 

From  the  above,  it  is  evident  that  lichens  are 
peculiar  plants  ;  they  are  the  result  of  the  mutualistic 


WHAT    ARE    LICHENS  ?  33 

association  of  a  fungus  and  an  alga,  two  morphologi- 
cally distinct  organisms.  We  shall  now  consider 
somewhat  more  in  detail  the  relation  of  lichens  to  both 
algae  and  fungi. 

II.     THE  RELATION  OF   LICHENS  TO  ALG^  AND  FUNGI. 

In  the  historical  review  we  have  already  indicated 
the  varied  positions  given  to  lichens  in  the  many  sys- 
tems of  classification.  Shortly  before  Schwendener's 
wonderful  discoveries  lichens  were  treated  as  a  distinct 
class  of  plants,  coequal  in  systematic  importance  with 
fungi,  algas  and  mosses.  .  Schwendener  and  his  fol- 
lowers unhesitatingly  classified  them  as  fungi.  "Why  ? 
Because  they  looked  upon  lichens  as  fungi  which  were 
parasitic  upon  algie*  Reinke,  de  Bary  and  others  have, 
however,  shown  conclusively  that  it  is  not  a  truly 
parasitic  relationship ;  as  already  indicated,  it  is  an 
association  mutually  beneficial,  known  as  mutualistic 
symbiosis.  Schwendener's  error  was  due  principally 
to  the  fact  that  he  misinterpreted  the  relationship  and 
laid  too  much  stress  upon  the  spore-bearing  structures. 
There  are  no  more  reasons  why  lichens  should  be 
classed  as  fungi  than  as  algse.  In  fact,  the  eminent 
scientist,  Nageli,  classified  them  as  algae  and  Tucker- 
man  in  his  earlier  writings  designates  lichens  as  "  aerial 
algae."  The  eminent  French  lichenologist,  Ny lander, 
had  already  recognized  the  double  affinity  of  lichens 
without  realizing  their  true  dual  nature.  In  his  sys- 
tem of  classification  he  begins  with  those  lichens  most 
nearly  resembling  fungi,  gradually  proceeding  to  the 
highest   foliose   and   fruticose  forms,  then  forming  a 


34  GUIDE    TO    THE    STUDY    OF    LICHENS. 

descending  series  with  those  most  nearly  resembling 
algae.  From  these  considerations,  it  is  evident  that 
the  attempt  to  classify  them  either  as  fungi  or  algae 
will  lead  to  confusion.  In  agreement  with  Reinke, 
Darbishire  and  others,  we  have  decided  to  treat  lichens 
as  a  distinct  class.  The  reasons  for  so  doing  will  be 
given  later. 

In  conclusion,  we  will  briefly  describe  the  algae 
which  enter  into  the  formation  of  lichens.  The  figures 
of  Plate  I  represent  the  algae  surrounded  by  the 
hyphal  network  of  the  fungal  symbiont.  The  fungal 
types  cannot  be  represented,  for  the  simple  reason 
that  they  are  not  known ;  the  knowledge  that  they  are 
derived  from  some  groups  of  the  sac-fungi  must  suffice 
for  the  present.  The  general  belief  is  that  the  fungi 
which  originally  entered  into  the  formation  of  lichens 
no  longer  exist.  There  are,  however,  fungi  now  liv- 
ing which  resemble  the  fungal  symbionts  of  certain 
lichens ;  for  example,  the  representatives  of  the  fungal 
genus  Hysterium  closely  resemble  the  fungal  symbiont 
of  the  lichen-genus  Ghraphis. 

I.  Chlorophyce^.  —  The  algae  belonging  to 
this  group  are  distinctly  bright-green.  The  follow- 
ing are  the  species  which  enter  into  the  formation  of 
lichens,  given  in  the  order  of  the  frequency  of  occur- 
rence. 

1.  Cystococcus  humicola.  This  is  a  unicellular  alga 
occurring  in  far  the  greater  number  of  lichens.  The 
cells  are  spherical.     (Fig.  1.) 

2.  Chroolepus    umhrina.      This    alga   forms    short 


WHAT    ARE    LICHENS?  35 

brandling  cliains  of  rather  oblong  irregular  cells  bear- 
ing brownish  substances  known  as  pyrenoid  bodies. 
(Fig.  2.) 

3.  Pleurococcus  vulgaris.  A  single-celled  alga  of 
rather  irregular  outline.  It  sometimes  has  a  bluish 
tinge.     (Fig.  8.) 

4'  Glceocapsa  polydermatica.  This  is  also  a  single- 
celled  alga.  It  differs  from  the  preceding  in  that  each 
cell  is  enclosed  by  a  thick,  transparent,  gelatinous  mem- 
brane.    (Fig.  4.) 

5.  Dactylococcus  infusionum.  A  single-celled  alga. 
The  cells  are  comparatively  small  and  regularly  ellipti- 
cal ;  they  are  usually  associated  in  colonies  of  eight  or 
ten  cells.     (Fig.  7.) 

II.  Cyanophyce^.  —  The  alg*  of  this  group  differ 
from  the  chlorophyce^e  in  their  blue-green  color. 

1.  Nostoc  lichenoides.  This  alga  occurs  in  chains 
of  rather  small  cells.  Each  chain  contains  one,  rarely 
more,  larger  cell  known  as  a  heterocyst.  Each  chain 
is  enclosed  by  a  gelatinous  substance.     (Fig.  3.) 

2.  Rivularia   nitida.      This    alga   also    occurs    in 

o 

chains,  but  its  cells  are  irregular  in  form.  Gelatinous 
substance  present.      (Fig.  5.) 

S.  Poly  coccus  punctiformis.  Tlie  cells  of  this  alga 
are  elliptical  and  occur  in  colonies  enclosed  by  a  com- 
mon covering.     (Fig.  6.) 

4.  Sirosiphon  puhinatus.  This  is  a  many-celled 
branching  alga  of  sufficient  size  to  be  seen  by  the 
naked  eye.  It  occurs  in  the  lichen-genus  Ephebe. 
(Fig.  9.) 


36  GUIDE    TO    THE    STUDY    OF    LICHENS. 

These  brief  references  to  the  algae,  with  the  accom- 
panying illustrations,  will  suffice  at  present,  as  they 
will  again  be  mentioned  in  the  discussion  of  lichen- 
genera. 

III.     LICHENS    AS    MORPHOLOGICAL    UNITS. 

We  shall  now  briefly  summarize  those  characteristics 
which  distinguish  lichens  from  other  plants,  fungi  and 
algae  in  particular.  This  is  very  necessary  in  the 
present  state  of  our  knowledge  of  lichens,  as  the  influ- 
ence of  Schwendener's  teachings  is  as  yet  very  strongly 
felt. 

Lichens  macroscopically  considered  present  such  a 
peculiar  appearance  that  the  most  superficial  observer 
is  led  to  believe  that  they  form  a  group  by  themselves. 
They  occur  in  places  where  neither  alga  nor  fungus 
could  exist  alone.  They  have  wonderful  powers  of 
resisting  extremes  of  temperature  ;  freezing  only  checks 
their  growth;  a  temperature  of  — 40°  C.  does  not  kill 
them.  They  will  resist  a  temperature  of  60°  C.  for 
an  hour  or  more.  They  can  tide  over  periods  of  dry- 
ness which  would  invariably  be  fatal  to  either  alga  or 
fungus  if  existing  alone. 

The  two  symbionts  form  a  microcosmos  which  is  en- 
abled to  perform  the  life-functions  originally  inherent 
in  both,  and,  in  addition,  the  lichen  has  acquired  new 
structural  and  functional  characters  during  its  phyl- 
ogeny.  The  morphological  adaptations  are  primarily 
for  the  furtherance  of  the  function  of  assimilation, 
while  among  fungi  the  structural  adaptations  are  pri- 
marily for  the  furtherance  of  the  function  of  reproduc- 


WHAT    ARE    LICHENS  r*  37 

tion.  The  method  of  reproduction  in  lichens  is  wholly 
different  from  that  of  fungi  as  well  as  algae.  It  is, 
however,  true  that  the  spores  of  lichens  have  a  close 
morphological  resemblance  to  the  spores  of  certain 
fungi,  but  functionally  they  differ  widely.  The  spores 
of  fungi  can  develop  into  new  spore-producing  in- 
dividuals, while  the  spores  of  lichens  cannot  produce 
new  lichens  unless  associated  with  the  essential  algae, 
which  proves  that  the  fungal  symbiont  can  no  longer 
mature  independently.  Some  of  the  lichen-algae  have 
been  induced  to  exist  independently,  but  it  is  evident 
that  some  cannot.  Lichen-spores  are  simply  the 
functionally  degenerate  reproductive  organs  of  their 
fungal  ancestors. 

As  already  indicated,  fungi  are  essentially  parasitic 
and  saprophytic.  Lichens  have  partially  or  almost 
wholly  lost  the  saprophytic  and  parasitic  function  and 
have  acquired  the  power  of  converting  inorganic  sub- 
stances into  organic  compounds.  The  thallus  of  lichens 
is  structurally  and  functionally  comparable  to  the  leaf 
of  higher  plants ;  fungi  have  no  thallus,  nor  do  they 
have  any  functional  resemblance  to  the  leaves  of  higher 
plants. 

Lichens  also  contain  chemical  compounds  not  found 
in  fungi  or  algae.  Among  these,  lichenin  (lichen-starch) 
is  the  most  important ;  others  are  various  acids  (ever- 
nic,  cetraric,  etc.)  and  bitter  extracts,  coloring  sub- 
stances, and  other  compounds  as  yet  not  well  known. 

The  typical  reproductive  organs  of  lichens  are  the 
soredia.  These  are  in  reality  miniature  thalli  espe- 
cially adapted  to  serve  as  propagative  organs.     They 


B8  GUIDE    TO    THE    STUDY    OF    LICHEKS. 

are  formed  of  the  elements  of  both  symbionts  and  can 
therefore  develop  into  a  new  lichen.  Their  structure 
and  function  will  be  more  fully  described  elsewhere. 
Lichens  are  also  more  long  lived  than  fungi.  The 
majority  of  fungi  terminate  existence  with  the  matura- 
tion of  the  spores,  while  most  lichens  have  an  indefin- 
itely prolonged  existence.  Some  of  the  Cladonicis,  for 
example,  may  live  hundreds  of  years  ;  the  apical  portion 
continues  to  grow,  while  the  basal  portion  dies  away. 

Sufficient  reasons  have  been  given  to  show  that 
lichens  are  neither  fungi  nor  algae ;  they  must  there- 
fore be  treated  as  a  distinct  class  of  plants.  Other 
characters  peculiar  to  lichens  will  be  mentioned  later. 


MORPHOLOGY    AND    PHYSIOLOGY.  39 


SECTION   IV. 

THE   MORPHOLOGY  AND  PHYSIOLOGY   OF 
LICHENS. 

We  have  already  explained,  in  a  general  way,  the 
morphological  structure  and  the  functional  activities 
of  lichens.  We  shall  now  enter  into  a  somewhat  more 
special  comparison  of  the  different  lichen-forms.  This 
is  necessary  to  a  better  understanding  of  the  relative 
functional  activities  of  lichens  and  their  tendency  in 
the  scale  of  evolution.  We  will  find  that  the  higher 
lichens  are  more  highly  specialized  as  chlorophyll- 
bearing  organisms,  and  tluit  the  evolutionary  ten- 
dency is  away  from  tlie  forms  resembling  fungi.  We 
will  find  that  there  is  a  reduction  in  the  spore-produc- 
ing function,  accompanied  by  an  increase  in  the  assim- 
ilative function. 

I.     THE    THALLUS. 

The  thallus  of  lichens  is  the  purely  vegetative  portion 
of  the  plant.  It  performs  the  function  of  assimilation, 
and  in  it  the  phenomena  of  growth  are  actively  mani- 
fest. It  is  comparable  to  the  vegetative  portion  of 
other  cryptogams,  such  as  mosses  and  liverworts.  In 
its  gross  appearance  and  general  texture,  it  is,  how- 
ever, very  characteristic ;  so  that  a  very  casual  ac- 
quaintance with  lichens  enables  one  to  distinguish 
them  from  all  other  thallophytes,  as  the  lower  flower- 
less  plants  are  technically  known. 


40  GUIDE    TO    THE    STUDY    OF    LICHENS. 

From  what  has  already  been  said  of  lichens,  the 
reader  knows  that  the  thallus  is  functionally  wholly 
different  from  the  vegetative  portion  of  fungi.  The 
main  difference  may  be  stated  as  follows  :  In  fungi 
the  structural  development  and  arrangement  of  tissue- 
elements,  of  the  vegetative  portion,  is  for  the  special 
purpose  of  furthering  the  function  of  reproduction, 
that  is,  to  supply  a  suitable  structural  arrangement 
for  the  maturation  and  distribution  of  the  spores.  In 
lichens  the  structural  development  and  arrangement 
of  the  tissue-elements  is  for  the  special  purpose  of 
furthering  the  function  of  assimilation. 

Structurally  and  functionally,  the  thallus  of  lichens 
is  also  analogous  to  a  foliage  leaf  of  higher  plants. 
This  becomes  apparent  on  comparing  vertical  sections. 
The  upper  and  lower  cortical  layers  of  the  thallus  are 
functionally  analogous  to  the  upper  and  lower  epider- 
mis of  the  leaf ;  the  algal  layer  of  the  thallus  to  the 
palisade  tissue  of  the  leaf ;  the  medullary  tissue  of  the 
thallus  to  the  spongy  tissue  of  the  leaf.  The  analogy 
is,  in  fact,  very  striking,  particularly  between  foliose 
thalli  and  the  ordinary  flattened  foliage  leaves.  Fru- 
ticose  thalli  are  analogous  to  leaves  with  "  isolateral " 
or  "centric"  structure.  Crustose  thalli  are  in  reality 
rudimentary  foliose  thalli,  and  are,  therefore,  remotely 
analogous  to  ordinary  foliage  leaves. 

For  practical  purposes,  the  thalli  of  all  lichens  may 
be  divided  into  three  types  or  kinds,  namely,  crustose, 
foliose,  and  fruticose.  Their  structural  differences  are 
as  follows : 


MORPHOLOGY    AND    PHYSIOLOGY.  41 

1.    The    Crustose    Type. 

This  thallus  occurs  in  the  lower  lichens,  that  is,  in 
those  in  which  the  evolutionary  specializations  as 
lichens  are  not  yet  highly  marked.  In  its  simplest 
form  it  consists  merely  of  a  network  of  hyphae  in 
which  are  suspended  a  few  algas  ;  it  may  occur  on  the 
substratum,  or  wholly,  or  partially,  beneath  its  sur- 
face. There  are  no  distinct  layers,  in  fact,  in  many 
instances  it  is  almost  impossible  to  detect  any  thallus 
whatever.  Such  rudimentary  thalli  occur  in  the  lower 
species  of  Calicium^  Pyrenula,  Trypethelium,  Xylo- 
grapha,  Arthonia  and  other  genera. 

The  higher  crustose  thalli  are  quite  thick,  as  in  Le- 
canora,  Pertusaria,  the  southern  representatives  of 
Gh'apkis,  in  Pceomyces,  and  other  genera.  The  sur- 
face is  often  warty  or  the  entire  thallus  is  marked  off 
into  many-sided  areas  or  areoles  and  is  therefore  spoken 
of  as  areolate.  In  higher  crustose  thalli  we  find  the 
tissue-elements  arranged  into  distinct  layers,  as  seen 
in  a  vertical  section.  The  upper  layer  consists  of 
hyphae  and  constitutes  a  protective  covering  for  the 
layer  of  algae  just  beneath.  The  algje  are  inclosed  by 
specialized  branches  of  hyphse,  spoken  of  as  haustoria. 
Below  the  algae  occurs  another  layer  of  hyphae  which 
attach  the  thallus  to  the  substratum  and  assists  in  tak- 
ing up  soluble  food-substances.  The  hyphae  forming 
the  upper  layer,  the  haustoria,  and  the  lower  layer  are 
continuous,  and  are  part  of  the  same  hyphal  tissue. 
In  many  instances  the  upper  layer  becomes  more  or 
less  distinctly  cortical,  thus  resembling  the  ui)per 
layer    of    foliose     thalli.       In    fact,    very    often    it 


4'2  GUIDE    TO    THE    STUDY    OF    LICHENS. 

is  difficult  to  determine  whether  a  given  thallus  is 
crustose  or  foliose.  A  typical  crustose  thallus  is 
always  closely  adnate  to  the  substratum  and  never  has 
a  lower  cortical  layer  ;  the  margin  sometimes  becomes 
lobed,  as  in  some  representatives  of  Placodium. 

It  is  questioned  whether  many  of  the  lower  crustose 
lichens  should  not  be  classified  as  fungi.  If  a  thallus 
is  present,  no  matter  how  rudimentary,  it  is  unmistak- 
ably a  lichen ;  it  must  be  remembered  that  careful 
search  is  often  necessary  to  detect  such  rudimentary 
thalli,  as  in  Pyrenula  and  other  genera.  (Plates  II 
and  IV.) 

2.    The  Foliose   Type. 

Most  of  the  lichens  with  which  the  amateur  collector 
will  come  in  contact  belong  to  the  foliose  type.  As 
a  rule,  the  thallus  is  large,  consisting  of  branching 
lobes  which  are  only  loosely  attached  to  the  substra- 
tum. In  some  instances  the  thallus  is  entire,  varying 
from  very  small,  as  in  Dermatocarpon  and  Psora,  to 
very  large,  as  in  JJtr^iUcaria  and  Gyrophora.  One 
thing  must  be  kept  in  mind  and  that  is  the  fact  that 
the  foliose  type  merges  into  the  fruticose  type  in  the 
ascending  series,  and  into  the  crustose  type  in  the  de- 
scending series.  The  characters  here  given  refer  to 
the  more  typical  forms  as  represented  by  the  Parmelias, 
Physcias,  Stictas,  Stictinas. 

If  we  make  a  vertical  section  of  the  thallus  and 
examine  it  under  the  microscope  we  find  the  following 
structures. 

1.  Upper  Cortical  Layer.  —  This  consists  of  a 
compact  tissue  of  short-celled  hyphae.     It  forms  a  pro- 


MORPHOLOGY    AND    PHYSIOLOGY.  43 

tective  layer  for  the  tissues  beneath  and  also  supplies 
mechanical  support  to  prevent  the  breaking  or  tear- 
ing of  the  thallus  due  to  winds  and  other  external 
forces.  The  upper  portion  of  this  layer  is  sometimes 
colored,  due  to  a  deposit  of  acid  crystals.  The  func- 
tion of  this  colored  substance  is,  perhaps,  twofold :  it 
probably  -modifies  the  influence  of  sunlight,  and  keeps 
away  animals  which  feed  upon  lichens,  such  as  snails. 
The  thickness  of  this  layer  varies  greatly  in  different 
lichens.  The  layer  is  often  not  uniform  in  thickness, 
even  in  the  same  plant;  for  example,  in  Peltigera  it  is 
alternately  thicker  and  thinner,  and  shows  a  remark- 
able double  adaptation  —  to  supply  the  required  mechan- 
ical support,  and  at  the  same  time  allow  the  algae  to 
approach  nearer  the  surface  for  the  purposes  of  greater 
chlorophyllian  activity  (carbon  assimilation). 

2.  Algal  Layer.  —  This  lies  beneath  the  layer  just 
described,  and  consists  of  a  loose  network  of  hypha?  in 
which  the  algae  are  suspended.  It  is  the  layer  in 
which  carbon  assimilation  is  carried  on.  Certain 
hyphal  branches,  the  haustoria,  enclose  and  even  pen- 
etrate the  algae,  and  take  from  them  the  assimilated 
food-substances  required  by  the  fungal  symbiont,  while 
the  alga  in  return  receives  water  and  certain  soluble 
food-substances  from  the  fungal  symbiont. 

3.  Medullary  Layer.  —  This  consists  of  a  very  loose 
network  of  hyphae.  It  contains  air,  and  therefore  the 
carbon  dioxide  required  to  carry  on  the  function  of  as- 
similation. The  thickness  of  this  layer  varies  con- 
siderably. 

^.    Lower    Cortical  Layer.  —  When    present  it  re- 


44  GUIDE    TO    THE    STUDY    OF    LICHENS. 

sembles  the  upper  cortical  layer,  usually  it  is  defi- 
cient, and  in  a  number  of  genera  it  is  wholly  wanting. 
When  wanting,  its  place  is  taken  by  a  tissue  of  hyphae 
which  extend  longitudinally.  From  the  lower  surface, 
whether  cortical  or  not,  the  rhizoids  extend.  These  are 
hyphae,  either  single  or  in  groups,  which  grow  verti- 
cally downward  into  the  substratum ;  they  sometimes 
remain  aerial  and  perhaps  serve  to  retain  moisture  or 
to  keep  off  crawling  insects  and  snails.  Usually  the 
rhizoids  are  colored  black.  The  cilia  at  the  marsfin  of 
many  foliose  thalli  are  morphologically  and  function- 
ally analogous  to  aerial  rhizoids.  (Plates  II,  III  and 
IV.) 

3.    The  Fruticose    Type. 

The  fruticose  thallus  differs  from  the  preceding  in 
that  the  lobes  of  the  thallus  are  distinctly  ascending 
and  are  not  attached  to  the  substratum.  The  entire- 
plant  is  attached  at  a  central  or  basal  point  known  as 
the  umbilicus.  It  must,  however,  be  remembered,  that 
the  umbilicus  is  also  present  in  some  foliose  thalli,  as 
Umbilicaria  and  Gyrophora.  The  umbilicus  consists  of 
a  hyphal  tissue,  and  is  analogous  to  the  roots  of  trees, 
holding  the  plant  firmly  attached  to  the  substratum 
and  taking  therefrom  moisture  and  soluble  food-sub-, 
stances. 

The  lobes  of  the  thallus  are  usually  much  branched, 
and  vary  from  distinctly  flattened  to  cylindrical.  The 
highest  and  most  perfect  type  is,  no  doubt,  represented 
by  Usnea  harbata. 

In  the  flattened  fruticose  thallus  we  find  the  follow- 
ing tissues,  which   are  essentially  like  corresponding 


MORPHOLOGY    AND    PHYSIOLOGY.  45 

tissues  of  the  foliose  thallus  :  1.  Upper  or  inner  corti- 
cal layer  ;  2.  Upper  or  inner  algal  layer  ;  3.  Medullary 
layer ;  4.  Lower  or  outer  algal  layer ;  5.  Lower  or 
outer  cortical  layer.  Rhizoids  are  not  present ;  cilia 
may  occur,  as  in  Cetraria  islandica. 

In  the  cylindrical  fruticose  thalli,  all  the  tissue-ele- 
ments are  arranged  in  a  cylindrical  fasliion.  The  cen- 
tral portion  may  be  hollow,  as  in  Cladonia  and  Pilo- 
phoron,  or  solid,  as  in  Usnea.  This  arrangement  of 
tissue-elements  is  in  accordance  with  mechanical  prin- 
ciples, giving  the  required  support  to  the  usually  large 
thalli.     (Plates  II  and  IV.) 

n.     THE    APOTHECIA. 

The  apothecia  are  the  spore-bearing  structures  de- 
veloped in  or  upon  the  thallus.  They  are  structurally 
very  similar  to  the  spore-})roducing  organs  of  fungi 
(Ascomycetes,  sac-fungi)  but  functionally,  the  similar- 
ity is  not  so  close.  Among  fungi,  each  spore  is  cap- 
able of  developing  into  a  mature  spore-producing 
plant;  that  is,  it  is  the  true  reproductive  element  of 
the  fungus.  In  lichens  it  is  essentially  different;  here 
the  spore  cannot  develop  into  a  new  spore-produc- 
ing plant  for  the  simple  reason  that  the  spore 
and  its  product  represents  only  a  part  of  the  lichen- 
autonomy  ;  that  is,  the  germinating  spore  must  be  asso- 
ciated with  the  requisite  algae  before  a  new  lichen  can 
develop.  This  difference  is  very  important  and  should 
be  kept  in  mind  when  comparing  lichens  and  fungi. 
The  spores  of  lichens  are  functionally  degenerate,  re- 
productive organs   derived  from    the  fungal  ancestor 


46  GUIDE    TO    THE    STUDY    OF    LICHENS. 

which  entered  into  the  formation  of  the  lichen  or 
lichen-group  under  consideration.  The  typical  repro- 
ductive organs  of  lichens  are  the  soredia,  which  shall 
receive  consideration  in  another  chapter. 

The  apothecia  have  undergone  certain  changes  dur- 
ing the  phylogenetic  history  of  the  lichen.  These 
changes  are  primarily  for  the  furtherance  of  the  func- 
tion of  assimilation,  rather  than  that  of  spore-formation. 
This  is  naturally  to  be  expected  since  the  spores  are 
of  little  value  as  reproductive  organs.  Many  of  the 
higher  lichens  are  constantly  sterile.  In  some,  the 
original  apothecial  structure  has  been  converted  into 
an  assimilating  organ,  that  is,  a  thallus.  The  vertical 
thallus  of  the  Gladonias,  usually  known  as  the  pode- 
tium,  is  doubtless  such  a  modified  apothecial  structure. 
Again,  the  "  cup  apothecia  "  of  some  lichens  have  be- 
come greatly  expanded,  and  contain  within  their  in- 
terior algae,  thus  acting  as  assimilating  organs.  In 
others,  particularly  the  lower  forms,  the  apothecia  re- 
tain the  structural  characters  of  their  fungal  ancestors  ; 
that  is,  they  do  not  bear  algae,  and  hence  do  not  take 
part  in  the  function  of  assimilation.  Upon  the  pres- 
ence or  absence  of  algae  are  based  the  distinctions  into 
fungal  and  thalline  apothecia. 

1.    The  Fungal  Type. 

This  apothecium  is  in  all  respects  similar  to  the 
apothecium  of  an  Ascomycetous  fungus.  The  algae  of 
the  algal  layer  of  the  thallus  do  not  enter  into  its 
formation.  It  may  be  cup-shaped,  as  in  the  Discomy- 
cetes,  or  immersed,  as  in  the  Pyrenomycetes.     In  the 


MORPHOLOGY    AND    PHYSIOLOGY.  47 

former  case,  the  following  structures  are  discernible  in 
a  vertical  section.  The  uppermost  layer  forming  the 
disk,  consists  of  the  spore-sacs  and  paraphyses.  The 
former  are  specialized  hyphae  which  contain  the  spores ; 
the  latter  are  also  specialized  hyphae,  placed  vertically, 
like  the  spore-sacs,  but  are  much  more  slender  and  do 
not  contain  spores.  This  layer  is  known  as  the  thecium  ; 
the  spore-sacs  are  also  known  as  thecce  or  thekes.  The 
term  spore-sacs  is,  however,  preferable,  as  it  expresses 
more  clearly  what  they  are.  The  upper  ends  of  the 
paraphyses  are  frequently  colored,  as  brown,  black, 
scarlet,  yellow,  etc.,  giving  the  disk  its  characteristic 
color,  as  discerned  by  the  naked  eye.  Below  the  the- 
cium occurs  the  hypothecium,  which  consists  usually, 
of  closely  united  hyphae,  generally  extending  at  right 
angles  to  the  spore-sacs  and  paraphyses.  This  tissue 
is  more  or  less  cup-shaped ;  in  the  Pyrenomycetous 
type,  it  formes  a  sphere,  enclosing  the  thecium.  In 
some  cases  it  is  convex,  rather  than  concave  or  cup- 
shaped,  as  in  Cladonia  and  Bceomyces. 

If  we  have  made  our  section  from  near  the  margin 
of  the  cup,  we  will  find  the  following  additional  tis- 
sues. 1.  Medullary  tissue  similar  to,  and  continuous 
with  the  medullary  tissue  of  the  thallus.  2.  Cortical 
tissue  similar  to  and  continuous  with  the  upper  corti- 
cal layer  of  the  thallus.  Sometimes  this  layer  is  not 
cortical.     (Plate  IV.) 

2.    The    Thalline   Type. 

This  differs  from  the  foregoing  in  that  the  algal 
layer   of    the    thallus    extends    into    the   apothecium, 


4^  GUlDE    to    TrtE    STUDY    OF    LICHENS. 

usually  forming  two  layers  ;  one  imnaediately  under- 
neath the  hypothecium,  and  the  other  just  above  the 
lower  cortical  layer  of  the  apothecium.  The  algae  may 
approach  quite  to  the  margin  of  the  cup,  or  they  may 
extend  only  a  part  way  up.  In  fact,  there  are  all 
gradations,  from  the  purely  fungal  type  to  the  most 
highly  developed  thalline  type  as  it  occurs  in  the 
Parmelias  and  in  Usnea.  In  general  it  may  be  stated 
that  the  fungal  type  occurs  in  the  lower  lichens,  while 
the  thalline  type  occurs  in  the  higher  lichens.  There 
are,  however,  important  exceptions  to  this  rule.  Figs. 
1  to  5  of  Plate  IV  will  serve  to  illustrate  the  differ- 
ences between  the  types  just  discussed. 

III.     ACCESSORY    STRUCTURE. 

The  thallus  and  apothecia  constitute  the  most  im- 
portant lichen-structures  ;  there  are,  however,  a  num- 
ber of  other  structures  which  occur  on  the  thallus, 
and  which  are  of  more  or  less  importance  in  the  lichen- 
economy,  and  for  that  reason  it  is  well  that  the  student 
should  be  somewhat  familiar  with  them.  They  are 
here  discussed  in  the  order  of  their  importance  : 

1.    The  Soredia. 

Examination  of  the  upper  surface  of  the  thallus  of 
many  lichens  reveals  patches  of  a  powdery  or  mealy 
substance.  These  patches  may  be  circular  or  linear, 
especially  along  the  margin  of  the  thallus.  If  some 
of  this  powder  is  placed  under  the  microscope  and 
examined,  it  is  found  to  consist  of  small  irregular 
bodies  made  up  of  a  hollow  network  of  hyphae,  in  the 


*       MORPHOLOGY    AND    PHYSIOLOGY.  49 

interior  of  which  algae  occur.  Each  body  is  in  reality 
a  miniature  thallus,  and  is  capable  of  developing  into 
a  new  lichen  should  it  find  a  suitable  lodging-place. 
It  is  the  true  propagative  organ  of  lichens.  The 
majority  of  lichens  depend  almost  wholly  upon  this 
method  of  reproduction. 

It  is  well  to  bear  in  mind  that  lichens  are  also 
propagated  in  a  purely  vegetative  way  ;  that  is,  a  portion 
of  a  lichen-thallus,  or  even  the  entire  thallus,  may  be 
torn  away  and  carried  to  a  new  locality,  where  a  por- 
tion of  it  will  develop  into  a  new  lichen.  Some  lichens 
also  possess  what  may  be  designated  as  continuous  re- 
juvenescence ;  that  is,  there  is  continuous  apical  growth, 
accompanied  by  a  continual  dying  away  of  the  older 
portion.  Tliis  phenomenon  occurs  typically  in  the 
higher  Cladonias  as  well  as  in  Thamnolia,  and  is  also 
met  with  in  the  higher  foliose  lichens,  as  Parmelia. 
The  central,  hence  older,  portion  dies  away,  while  the 
margin  continues  to  grow,  producing  an  appearance 
not  unlike  the  "fairy  rings"  of  certain  mushrooms. 
Nevertheless  the  soredia  constitute  the  most  important 
means  of  propagating  lichens.  They  are  developed 
from  the  algal  layer  of  the  thallus,  finally  pushing 
their  way  through  the  upper  cortical  layer  to  the  ex- 
terior. Each  body  is  known  as  a  soredium  ;  a  collec- 
tion of  them  forming  one  of  the  patches  above  men- 
tioned is  designated  as  a  soralium,  plural  soralia. 

2.    The    Cyphellce. 

Upon  examining  the  lower  surface  of  the  thallus  of 
a  Sticta  or  Stictina  there  will  be  found  a  number  of 


50  GUIDE    TO    THE    STUDY    OF    LICHENS.  • 

lighter-colored  specks,  somewhat  smaller  than  a  pin- 
head  ;  these  are  the  cyphellce  and  are  functionally  anal- 
ogous to  the  stomata  or  breathing  pores  of  true  foli- 
age leaves.  Structurally  there  is  no  resemblance ; 
they  are  simply  breaks  in  the  lower  cortical  layer, 
filled  in  by  a  loose  secondary  cortical  tissue.  Upon 
examining  them  with  a  hand-lens,  it  will  be  found 
that  they  are  of  two  kinds  :  one  which  appears  as  a 
depression,  that  is,  concave ;  the  other  is  somewhat 
protruding  or  convex.  They  occur  only  in  the  genera 
indicated. 

3.    The   Cephalodia. 

These  are  wart-like  outgrowths,  usually  occurring 
on  the  upper  surface  of  the  thallus.  Sometimes  they 
also  occur  on  the  lower  surface,  as  in  Sticta  Oregana. 
They  are  simply  neo-formations  in  the  tissue  of  the 
thallus,  induced  by  a  foreign  alga.  They  occur  upon 
various  lichens,  but  are,  perhaps,  most  common  among 
the  Peltigeras  and  Stictas.  In  Peltigera  aphthosa 
they  are  very  numerous  and  are  about  the  size  of  a 
pin-head.  In  Sticta  Oregana  they  vary  from  very 
small  to  nearly  the  size  of  a  pea.'  These  two  plants 
also  typify  the  two  kinds  of  cephalodia.  In  Peltigera 
they  develop  upon  the  thallus,  while  in  Sticta  they  de- 
velop within  the  thallus.  Nothing  definite  is  known 
regarding  their  origin  and  function. 

Jf..    The  Spermagonia. 

These  are  very  minute  cup-shaped  structures,  im- 
mersed in  the  upper  surface  of  the  thallus.  To  the 
naked  eye  they  appear  as  minute  black  specks.    Noth- 


MORPHOLOGY    AND    PHYSIOLOOxY.  51 

ing  definite  is  known  regarding  their  function.     Some 
investigators  suppose  them  to  be  tlie  male  reproductive 
organs  of   lichens;  others  are  inclined  to  look  upon 
them   as   parasitic   fungi.     Many  lichenologists  have 
made  the  sad  mistake  of  considering  them  as  of  great 
importance  in  classification  ;  as  such  they  are  of  little 
significance,  because  they  are  too  variable  in  their  oc- 
currence, and  too  closely  similar  in  structure.    The  so- 
called  Pycnidia  are  closely  related  to  the  Spermagonia. 
It  is  not  at  all  likely  that  the  reader  will  care  to 
make  any  careful   examination   of   the  spermagonia. 
Should  he,  however,  do  so,  he  will  find  that  each  sper- 
magonium  resembles  a  small  apothecium.     In  place  of 
the    thecium  occur   hyphal  branches  {sterigmata)  on 
which   minute   acicular   or   rod-shaped    bodies    {sper- 
matia)  are  borne. 


52  GUIDE   TO    THE    STUDY^  OF   LICHENS. 


SECTION  V. 

THE   OCCUERENCE  AND   DISTRIBUTION  OF 
LICHENS. 

The  actual  number  of  species  of  lichens  occurring 
on  the  entire  globe  is  not  known.  According  to  Ny- 
lander,  about  1,500  species  were  recognized  in  1858 ; 
between  4,000  and  5,000  species  and  varieties  were 
recognized  in  1892,  according  to  Hue.  The  United 
States  contains  perhaps  between  800  and  1,000  species. 
It  must,  however,  be  remembered,  that  all  estimates 
are  more  or  less  unreliable.  Many  years  of  careful 
study  are  required  in  order  to  get  at  reliable  data  re- 
garding the  actual  number  of  lichen-species. 

I.     THE     LATITUDINAL     AND     ALTITCDINAL    DISTRIBU- 
TION    OF     LICHENS. 

Lichens  extend  to  the  far  north,  where,  with  a  few 
mosses,  they  form  the  most  advanced  outposts  of  vege- 
table life ;  they  extend  within  a  short  distance  of  the 
northern  snow  limit.  In  the  high  arctic  regions  they 
constitute  the  characteristic  flora  of  the  country.  Here 
they  occur  mostly  as  earth-lichens  and  rock-lichens,  dif- 
ferent species  growing  in  close  association,  forming  what 
are  technically  known  as  "  lichen-tundra."  The  great 
majority  of  species  belong  to  the  genera  Cetraria, 
Gladonia,  and  Evernia,     The  cause  for  their  occur- 


OCCURRENCE    AND    DISTRIBUTION.  53 

rence  as  earth-lichens  is  quite  evident,  as  scarcely  any- 
other  substrata  exist;  trees,  fences,  and  the  like 
being  wanting.  Jn  the  more  temperate  regions  we 
find  earth-lichens,  rock-lichens  and  a  considerable  num- 
ber of  tree-lichens.  In  the  tropics  tree-lichens  pre- 
dominate, owing  to  the  greater  competion  for  space. 
The  richness  of  vegetation  of  all  sorts,  trees  among  the 
rest,  makes  it  evident  that  vegetable  substrata  are,  in  a 
sense,  forced  upon  the  lichens.  In  fact,  the  intimate 
associations  of  plants  with  plants  and  of  animal  with 
plants,  etc.,  are  much  more  prevalent  in  the  tropics, 
for  similar  reasons.  The  great  struggle  for  existence 
necessitates  the  establishment  of  mutual  adaptations 
as  well  as  antagonism  or  parasitism. 

Some  lichens  have  a  limited  range,  wliile  others  are  ' 
truly  cosmopolitan,  such  as  Oladonia  rangiferina, 
Usnea  barbata,  Lecanora  subfusca  and  others.  As  to 
substrata,  some  species  are  limited  to  a  given  rock- 
formation,  while  others  occur  upon  different  rock- 
formations  as  well  as  upon  trees,  and  even  soil,  such 
as  many  of  the  Parmelias  and  Physcias.  Trees  (bark), 
rocks  and  soil  are  the  principal  substrata  for  lichens; 
they  are  also  common  upon  dead  (not  rotten)  wood, 
such  as  fences,  roofs  of  buildings,  etc.  Exceptionally 
they  have  been  found  growing  upon  rotten  wood, 
old  leather,  bones,  glass,  iron  railings,  etc.  Some  are 
truly  parasitic  upon  the  green  leaves  of  plants  in  the 
tropical  and  subtropical  regions. 

Crustose  lichens  very  frequently  encroach  upon  each 
other,  the  stronger  and  more  rapidly  growing  species 
finally  spreading  over  and  destroying  the  less  resist- 


54  GUIDE    TO    THE    STUDY    OP    LICHENS. 

ing  species.  The  same  thing  occurs  among  foliose 
and  fruticose  lichens.  A  great  many  lichens  show  a 
decided  preference  for  mosses,  over  which  they  spread 
in  considerable  profusion,  finally  killing  the  mosses, 
not  so  much  as  the  result  of  drawing  any  nourishment 
from  them,  but  rather  as  the  result  of  mechanical  in- 
terference and  the  shutting  off  of  air  and  sunlight. 

In  general  it  may  be  stated,  that  lichens  occur  plen- 
tifully from  the  northern  limit  indicated  to  the  tropics. 
Some  lichens  are  essentially  southern,  others  northern 
or  western.     Only  a  very  few  are  typically  eastern. 

It  is  quite  important  that  the  collector  should  have 
some  knowledge  of  the  vertical  distribution  of  lichens  ; 
this  will  avoid  much  waste  of  time  in  searching  for 
lichens  in  places  where  they  do  not  occur.  For  exam- 
ple, Gyrophoras  and  Umhilicarias  do  not  occur  at 
slight  elevations  ;  in  fact,  the  lowlands  yield  only  com- 
paratively few  lichens.  As  a  rule,  lichens  which  occur 
at  low  levels  in  the  arctic  regions  also  occur  at  high 
altitudes  in  the  warmer  or  tropical  regions. 

As  already  indicated,  mountainous  timber  regions 
yield  the  most  numerous  and  finest  specimens  of 
lichens  ;  prairies  and  open  lowlands  yield  the  poorest 
and  fewest.  It  also  seems  that  there  is  a  narrow  belt 
in  the  immediate  vicinity  of  the  coast  which  is  deficient 
in  lichens ;  this  is  perhaps  due  to  excessive  moisture, 
which  is  detrimental  to  their  existence.  We  have 
elsewhere  indicated  that  lichens  flee  from  civilization. 
The  reasons  for  this  are  not  definitely  known  ;  it  is 
very  likely  due  to  the  dust  and  smoke  (impure  atmo- 
sphere) of  the  cities ;  they  require  pure  air  for  their 


OCCURRENCE    AND    DISTRIBUTION.  55 

existence.  One  need,  therefore,  waste  no  time  in 
looking  for  a  rich  harvest  of  lichens  in  city  parks, 
along  much-travelled  roadsides,  in  woods  that  are  fre- 
quently  run  over  by  cattle,  sheep,  and  oth'^r  animals. 
Seek  the  highest  and  wildest  hills  in  your  locality;  if 
there  are  none,  search  through  the  timber-lands;  if 
that  particular  locality  is  without  hills,  mountains,  and 
timber,  devote  yourself  to  the  orchard,  the  fences,  old 
buildings,  trees  along  roadsides,  etc.  Make  the  best 
of  your  locality  and  make  excursions  to  other  more 
favorable  areas.  Further  particulars  in  regard  to  the 
occurrence  of  lichens  will  be  given  in  the  description 
of  genera  and  species. 


56  GUIDE    TO    THE    STUDY    OF    LICHENS. 


SECTION  VI. 

LICHENS  AND  THE   NATURALIST. 

It  is  hoped  that,  from  the  consideration  of  the  pre- 
ceding chapters,  the  reader  has  obtained  a  fair  knowl- 
edge of  the  true  nature  of  a  lichen,  so  that  there  will 
be  no  difficulty  in  recognizing  at  least  the  higher  forms. 
The  origin  and  structure  of  lichens  has  been  explained, 
so  that  there  is  no  excuse  for  confounding  them  with 
fungi  or  mosses,  or  to  designate  them  as  "  dead  things," 
"excrescences,"  or  "nothing  much."  Each  lichen 
will  bring  up  some  association,  with  the  history  of 
its  evolution,  its  treatment  in  the  hands  of  the  botan- 
ists of  the  past,  its  uses  in  the  arts  and  in  medicine,  its 
relation  to  other  plants,  its  work  in  nature,  etc.  All 
this  will  serve  as  food  for  thought  while  on  a  collecting 
trip.  It  is  now  our  purpose  to  indicate  briefly  how 
to  collect,  study  and  preserve  lichens. 

I.     THE    COLLECTION    OF    LICHENS. 

Lichens  may  be  collected  all  the  year  round,  but 
there  are  seasons  which  are  more  suitable  than  others ; 
such  as  late  in  the  summer  and  in  the  autumn,  because 
then  the  thalli  and  the  apothecia  are  at  their  best. 
The  great  majority  of  lichens  live  from  year  to  year, 
and  can,  therefore,  be  collected  at  any  time  ;  some  be- 
gin development  and  mature  in  one  season,  such  as  the 


LICHENS    AND    THE    NATURALIST.  57 

Collemas ;  these  in  particular  should    he  collected  in    ' 
the  fall. 

Having  decided  upon  the  most  favorable  season  for 
collecting,  we  find  that  there  are  days  and  portions  of 
a  day  which  are  particularly  suited  for  this  work.  Just 
after  a  rain  lichens  show  their  brightest  colors  and 
become  greatly  enlarged,  owing  to  the  absorption  of  ' 
water.  At  this  time  the  foliose  and  fruticose  lichens 
are  not  in  the  least  brittle ;  they  can  be  bent  or  rolled 
without  any  danger  of  breaking  them.  In  the  morn- 
ing and  early  forenoon  is  the  next  best  time  in  which 
to  collect.  The  worst  period  of  a  bright  day  is  at  noon 
or  in  the  early  afternoon  between  twelve  and  three 
o'clock.  Quite  early  in  the  evening  lichens  again  take 
up  moisture  and  lose  their  brittleness.  In  the  case  of 
crustose  rock  and  tree-lichens,  the  moisture  or  dryness 
of  the  thallus  is  of  no  consequence ;  they  might,  there- 
fore, be  collected  during  dry  weather,  or  during  the 
dry  periods  of  the  day.  Foliose  and  fruticose  rock- 
lichens  lose  their  moisture  first,  next  come  the  tree- 
lichens,  and  last  of  all  the  lichens  of  the  soil. 

No  expensive  or  complicated  outfit  is  needed  to  col- 
lect lichens  ;  cumbersome  and  not  absolutely  necessary 
traps  should  not  be  carried  about.  We  will  briefly 
describe  the  equipment  of  a  collector  who  intends  to 
put  in  a  day's  work  in  a  locality  where  lichens  are  quite 
plentiful.  As  to  the  clothing  to  be  worn,  it  need  not, 
of  course,  be  explained  that  it  is  not  a  dress-suit  affair; 
put  on  good  stout  old  clothing,  a  broad-brimmed  felt 
hat,  and  stout  shoes  with  thick  soles.  It  is  well  and 
advisable  to  carry  along  a  lunch,  and,  above  all,  make 


58  GUIDE    TO    THE    STUDY    OF    LICHENS. 

plans  to  enable  you  to  secure  a  drink  of  water ;  if  you 
know  of  a  spring,  that  is  just  the  thing,  keep  it  in  mind 
and  head  for  it  at  the  appropriate  time ;  if  no  spring 
exists  in  the  locality,  head  for  a  farm-house.  Never 
drink  out  of  small  brooklets,  especially  in  inhabited 
localities :  there  is  always  more  or  less  danger  of  be- 
coming infected  with  some  disease  germs,  or  perhaps 
some  intestinal  parasite.  The  collecting  outfit  may 
be  divided  into  three  groups,  as  follows  : 

1.  Contrivances  for  carrying  lichens. 

2.  Mechanical  aids  in  collecting. 

3.  Aids  to  a  temporary  study  of  lichens. 

1.  The  most  convenient  contrivance  for  carrying 
lichens  is  the  botanist's  collecting-can,  more  technically 
known  as  a  vascuhim.  This  can,  however,  only  be 
secured  ready-made  from  dealers  in  botanical  supplies. 
Any  tinsmith  can  make  one  to  order,  for  perhaps  $1.00, 
or  $1.50,  provided  it  is  explained  to  him  how  to  make 
it.  The  most  convenient  box  for  collecting  lichens 
should  be  rectangular,  with  corners  rounded,  made  of 
heavy  tin.  It  has  a  door  at  the  side  or  top.  It  should 
have  a  coat  of  black  japan  on  the  outside  to  prevent 
the  annoying  reflection  of  sunlight.  The  size  of  the 
box  can  be  left  to  the  taste  and  needs  of  the  individual. 
If  a  botanical  collecting-box  is  not  convenient,  an  old 
hand-satchel  will  do  very  well,  in  fact,  in  many  re- 
spects it  is  superior  to  the  tin  box. 

It  is  supposed  that  the  collector  intends  to  bring 
home  crustose  rock-lichens  and  crustose  tree-lichens 
as  well  as  foliose  and  fruticose  lichens.  The  rock- 
specimens  should  be  wrapped  in  paper  separately,  to 


LICHENS    AND    THE    NATURALIST.  59 

prevent  abrasion,  and  placed  in  tlie  bottom  of  the  vas- 
culum  or  satchel ;  on  top  of  these  place  tlie  bark-lichens, 
and  finally,  uppermost,  the  foliose  and  fruticose' 
lichens.  Or  the  rock  and  bark-lichens  may  be  placed 
in  the  box  as  indicated,  while  the  large  lichens  may  be^ 
placed  in  a  special  folio  made  of  two  broad  thhi  boards 
or  heavy  pasteboard,  with  a  back  and  suitable  handles. 
The  lichens  should  be  spread  between  folded  sheets  of 
paper  (newspaper  or  any  other),  care  being  taken  not 
to  crush  them  while  dry  ;  if  dry,  moisten  them,  when  . 
they  may  be  pressed  in  any  position  without  injury. 

2.  The  collector  will  require  the  following  instru- 
ments to  aid  him  in  securing  specimens :  a.  A  good, 
large  jack-knife  for  securing  bark-lichens,  especially 
the  crustose  forms.  This  should  be  quite  sharp  and 
may  be  carried  in  the  pocket,  b.  A  hammer  of 
medium  size,  and  a  cold-chisel  of  medium  size  for 
securing  crustose  rock-lichens.  These  might  be  car- 
ried in  a  leathern  pouch,  such  as  is  used  by  geologists, 
which  would  also  serve  to  carry  the  rock-specimens. 
c.  A  carpenter's  chisel,  or  a  table-knife,  will  be  found 
convenient  for  removing  large  foliose  lichens  from 
rocks,  fences  and  trees. 

It  now  only  remains  to  give  some  general  advice  as 
to  where  and  how  to  collect.  From  what  has  been 
said  of  the  distribution  of  lichens,  it  is  known  that 
mountainous  and  wooded  districts  yield  the  richest 
harvest ;  thickly  populated  and  open  districts  are  the 
poorest  in  the  variety  of  fine  specimens.  It  is  never 
advisable  to  proceed  from  a  poor  district  to  one  rich 
in  species.     It  is  only  a  waste  of  time'  and  energy  to 


60  GUIDE    TO    THE    STUDY    OF    LICHENS. 

collect  poor,  scrawny  specimens,  which  will  be  cast 
aside  as  better  material  is  found.  It  will,  of  course, 
not  be  necessary  to  urge  the  advice  not  to  begin  the 
collection  with  the  more  insignificant  crustose  forms ; 
the  beginner  will  only  too  gladly  leave  these  alone. 
For  some  time  attention  should  be  devoted  to  the 
larger  foliose  and  fruticose  lichens  and  to  collect  fer- 
tile material  in  so  far  as  that  is  possible.  It  must, 
however,  be  remembered  that  some  lichens  rarely  or 
never  bear  apothecia.  These  may  be  collected  and 
retained  until  the  fertile  forms  have  been  studied, 
when  little  difficul  ty  will  be  found  in  classifying  them, 
at  least  generically. 

lichens  occur  in  nearly  all  places  where  there  is 
ii  not  too  much  constant  moisture  and  shade.  They  are 
most  numerous  on  the  "  weather-side "  (northern  ex- 
posure) of  trees,  fences,  old  roofs  and  stone  walls. 
Travellers  and  hunters  have  time  and  again  utilized 
this  knowledge  to  guide  them  in  their  journeys.  Large 
specimens  of  lichens  occur  on  the  bleakest  rock ;  fine 
specimens  of  Cladonia  occur  on  the  soil  in  compara- 
tively open  ground ;  some  large  foliose  species  (Pelti- 
ffera)  occur  on  the  soil  in  shaded  places.  Bceornyces 
J  roseus,  with  its  pink'  apothecia,  which  is  quite  striking 
in  appearance  although  it  is  one  of  the  crustose  forms, 
also  occurs  on  the  soil. 

From  a  study  of  the  table  of  the  continental  range 
of  lichens  one  can  obtain  some  idea  as  to  what  genera 
may  possibly  be  met  with  in  a  given  locality.  A  col- 
lector in  the  eastern,  southern,  or  central  states  need 
waste  no  time  looking  for  Rocella  tinctoria^   as   this 


LICHENS    AND    THE    NATURALIST.  61 

lichen  occurs  on  the  Pacific  coast.  Graphis,  Arthonia 
and  a  few  other  genera  are  largely  southern,  etc.  It 
is  also  well  to  fix  in  mind  their  altitudinal  distribution, 
80  that  no  time  will  be  wasted  in  looking  for  lichens 
in  the  lowlands  which  occur  only  at  considerable  eleva- 
tions. 

In  a  general  way  it  may  be  advised  to  begin  the 
collection  with  the   highest  altitudes  and    to  descend 
gradually,  carefully  examining  trees,  rocks    and  soil. 
Rocky  ledges  at  high  altitudes  will  be  covered  by  large 
foliose  and  fruticose  lichens,  as  well  as  a  host  of  crus- 
tose  forms.     Some  of  the  Parmelias  may  be  several 
feet  in  diameter.     If   the  rock  is  not  too  rough   the 
lichen  can  be  peeled  off  readily :    begin  on  one  side, 
with  the  carpenter's  chisel,  or  the  table-knife,  gradually 
loosen  it  and  roll  the  edge  over,  keep  on,  slowly  and  ^ 
patiently,  and  you  will  succeed  in  removing  it  entire ; 
if  the  plant  is  dry  and  brittle  it  will  be  necessary  to 
moisten    it   with  water   before   trying    to    remove   it. 
After  it  is  removed  lay  it  flat  between  two  sheets  of 
paper  and  place  it  in  the  portfolio,  or  leave  it  rolled 
up   and   put  it  in  the  collecting-box.      Umbilicarias, 
Gyrophoras,  Stereocaulon,  Gladonia  and  some  others, 
will  occasion  no  trouble  in  removing  them  from  rock, 
as  they  are  only  loosely  attached.     If  they  are   dry 
and  brittle  it  is  well  to  moisten  them  before  handling 
much.     Some  difficulty  will  be  encountered  in  remov- 
ing foliose  lichens  from  the  bark  of  trees ;  usually  only 
fragments  can  be  obtained.     The  fruticose  lichens,  no 
matter  where   they  occur,  can  be  collected  with  but 
little    difficulty.     Crustose    bark-lichens    require    the 


y^ 


62  GUIDE    TO    THE    STUDY    OF    LICHENS. 

aid  of  the  jack-knife  or  perhaps  the  carpenter's  chisel 
and  the  hammer.  Crustose  rock-lichens  require  the 
use  of  the  cold-chisel  and  the  hammer.  If  the  rock  is 
stratified,  or  "  chips  "  easily,  no  difficulty  will  be  en- 
countered, but  if  the  rock  is  not  stratified,  for  example, 
granite,  the  chisel  is  of  little  value  ;  the  best  that  can 
be  done  is  to  knock  off  fragments  of  the  rock  from 
the  corners  ;  it  will  be  impossible  to  get  thin  specimens. 

Each  specimen,  as  it  is  collected,  should  be  carefully 
examined  with  a  lens  carried  for  that  purpose  ;  search 
for  apothecia,  observe  the  color,  size,  and  general 
contour ;  where  does  it  grow  —  on  rocks,  trees,  or  soil  ? 
the  altitude,  locality,  etc.  These  points,  and  others 
which  may  seem  interesting,  should  be  entered  in  a 
note-book ;  they  will  be  found  very  useful  in  the  sub- 
sequent study  of  the  specimen.  A  leisurely  collector 
may  take  with  him  a  guide  to  the  study  of  lichens  and 
determine  at  least  some  of  the  material  collected,  but 
this  is  not  at  all  urged,  as  the  final  studying  of  the  ma- 
terial is  to  be  done  at  home. 

Collected  material  requires  no  immediate  care.  It 
may  be  kept  tied  up  in  bundles  until  wanted  for  study, 
or  until  it  is  intended  to  prepare  the  specimens  for 
mounting.  One  thing  must,  however,  be  remembered  : 
do  not  stow  away  large  packages  of  lichens  in  a  moist 
place,  because  in  a  few  days  they  will  be  covered  over 
with  mould,  thus  ruining  the  specimens.  Another 
thing  to  be  guarded  against,  is  not  to  keep  thoroughly 
wet  specimens  wrapped  in  bundles  for  more  than  a  few 
hours,  as  many  species  will  change  color,  the  result  of 
chemical  processes ;  this  is  particularly  true  of  some 


LICHENS    AND    THE    NATURALIST.  63 

of  the  Parmelias.     In  view  of  these  facts,  it  would, 
therefore,  be  advisable  to  expose  the  collected  material  ' 
to  sunlight  until  they  are  quite  dry  ;  they  can  then 
be  safely  stored  away  for  an  indefinite  period  of  time. 

II.     THE    STUDY    OF    LICHENS. 

About  the  first  thing  to  be  done  with  the  collected 
material  is  to  study  it  critically,  with  a  view  to  deter- 
mining the  species.  This  can  best  be  done  at  home, 
where  the  necessary  apparatus  and  conveniences  may 
be  employed.  It  is  also  taken  for  granted  that  no 
previous  experience  has  been  had  in  identifying  lichens. 

Place  the  collected  material  on  a  convenient  table; 
now  sort  the  lichens  into  heaps,  placing  those  that 
look  alike  together.  Compare  them  carefully  as  to 
color,  branching,  size,  and  form  of  the  apothecia,  etc. 
Make  liberal  use  of  the  pocket  lens,  and  have  the  field 
note-book  at  hand  for  reference.  If  the  specimens  are 
dry  and  brittle  moisten  them  by  dipping  in  a  basin  of 
water  ;  this  will  also  restore  their  natural  color.  The 
number  of  heaps  indicates  approximately  the  number 
of  species  collected. 

The  next  step  in  the  procedure  is  to  select  one  of 
the  heaps  of  which  the  specimens  have  well-developed 
apothecia.  It  is  preferable,  in  most  instances,  to  begin 
with  fruticose  forms,  only  it  must  be  remembered  that 
many  of  them  are  normally  sterile,  that  is,  tliey  are 
without  apothecia. 

The  next  thing  to  be  done  is  to  determine  the  fam- 
ily to  which  the   plant  under   consideration  belongs. » 
This  can  be  accomplished  with  the  aid  of  the  key  and 


64  GUIDE    TO    THE    STUDY    OF    LICHENS. 

diligent  study  of  the  description  of  families.  The 
method  of  procedure  in  the  identification  of  the 
genus  depends  somewhat  upon  whether  or  not  a  com- 
pound microscope  is  available.  If  a  microscope  is  at 
hand  the  genus  may  be  determined  from  the  examina- 
tion of  the  spores,  and  incidentally,  also,  the  algae. 
All  that  is  necessary  is  to  take  very  minute  bits  of 
the  thallus  and  apothecium,  tear  them  apart  thoroughly, 
mount  in  water  and  examine.  If  the  fragments  are 
still  too  thick,  carefully  press  upon  the  cover-glass,  ac- 
companying the  pressure  with  a  rotary  motion  of  the 
finger ;  this  will  separate  the  tissue-elements  sufficiently 
to  permit  their  being  seen  distinctly.  If  no  microscope 
is  at  hand,  the  only  thing  that  remains  to  be  done  is 
to  do  the  best  you  can  without  it ;  the  "  artificial 
key  "  is  especially  prepared  for  those  who  are  without 
/  a  compound  microscope.  No  attention  need  be  paid, 
in  this  latter  case,  to  spore-characters  and  the  alg£e ; 
make  use  of  the  family-characters  and  generic  charac- 
ters given  in  Part  II. 

After  the  genus  is  determined,  it  only  remains  to 
identify  the  species.  This  is  done  by  referring  to 
the  descriptions  of  the  species  belonging  to  that  genus. 
The  beginner  must  not  feel  discouraged  should  he  be 
unable  to  name  all  the  species  collected,  it  is  not  ex- 
pected of  him.  The  unnamed  specimens  should  be 
kept  for  future  study,  or  they  may  be  submitted  to  an 
expert  for  identification.  It  is  well  to  bear  in  mind 
that  the  expert  cannot  afford  to  do  this  work  gratis ; 
in  perhaps  most  instances  he  will  be  satisfied  with  a 
duplicate  set 


LICHENS    AND    THT:    NATURALIST.  65 

It  would  also  be  advisable  for  the  beginner  to  pur- 
chase a  set  of  lichens  already  named  by  some  good 
autliority  on  lichens.  A  set  of  from  fifty  to  one  hun- 
dred lichens  typical  of  the  United  States  can  be  had 
for  from  five  to  ten  dollars.  These  lichens  would  be 
found  very  useful  as  helps  in  the  identification  of  most 
genera  and  species. 

This  general  advice  is  intended  to  point  out  the  way 
as  to  the  procedure  in  the  identification  of  species. 
Great  patience  is  necessary.  Do  not  expect  impos- 
sibilities ;  if  you  determine  one  out  of  every  six 
species  collected  you  have  done  well ;  if  you  deter- 
mine them  all  you  are  a  genius  and  should  make  lichen- 
ology  your  life-work.  In  any  case  the  mere  name  adds 
little  to  our  appreciation  of  the  lichen ;  it  is  the 
knowledge  of  its  true  relation  to  other  things  which 
makes  it  interesting. 

III.    THE    PRESERVATION    OF    LICHENS. 

Fortunately  lichens  are  very  easily  preserved ;  they 
require  less  care  than  any  of  the  other  groups  of  plants. 
Some  skill  is,  however,  necessary  to  prepare  a  really 
fine  collection,  or  herharirim,  as  it  should  be  more  tech- 
nically called.  Some  collectors  will  no  doubt  find  use 
for  lichens  for  decorative  purposes,  but  the  prime  ob- 
ject of  the  great  majority  of  lichenologists  in  making 
collections  will  be  to  arrange  them  in  some  suitable 
manner,  with  the  view  to  accumulating  a  lichen-herba- 
rium of  fine,  large,  well-preserved,  well-mounted  speci- 
mens. With  this  in  mind,  we  shall  consider  especially 
the  preservation  of  the  foliose  and  fruticose  lichens. 


66  GUIDE    TO    THE    STUDY    OF    LICHENS. 

The  collected  material  usually  has  clinging  to  it 
various  foreign  substances,  such  as  soil,  leaves,  twigs, 
moss,  particles  of  bark  and  decayed  wood,  etc.  It  is 
desirable  to  remove  these  as  far  as  possible.  A  little 
experience  in  cleaning  them  will  teach  how  this  can 
be  done  best  and  most  expeditiously.  Much  of  the  soil, 
sand,  and  other  substances  can  be  shaken  out ;  wash- 
ing and  rinsing  in  plenty  of  water  will  readily  remove 
dust  and  dirt.  Leaves,  moss  and  twigs  can  be  picked 
out  with  a  pair  of  tweezers.  Each  specimen  should 
be  carefully  cleaned.  If  the  specimens  have  been 
washed,  lay  them  where  the  water  can  drain  off.  All 
v^  specimens  should  be  moistened  before  they  are  pressed, 
but  it  must  be  remembered  that  there  should  be  no  ex- 
cess of  water  present. 

The  next  step  in  the  procedure  is  to  dry  and  press 
the  cleaned  specimens.  For  this  purpose,  sheets  of 
blotting-paper  are  necessary,  or,  better  still,  the  regu- 
lation dryers  used  by  botanists.  Place  one  of  the 
sheets  of  blotting-paper  or  dryer  on  a  piece  of  board 
or  on  a  table,  on  this  place  a  sheet  of  paper  (news- 
paper will  answer  very  well).  Now  take  the  moder- 
ately dry  specimens  (they  must  be  sufficiently  moist  to 
be  thoroughly  soft  and  pliable)  and  arrange  them  as 
you  wish  them  to  appear  in  the  collection.  If  a  foliose 
lichen,  of  course  the  entire  thallus  is  simply  laid  flat. 
If  fruticose,  arrange  the  branches  as  artistically  (natu- 
rally) as  possible.  Cover  the  entire  sheet,  but  do  not 
place  specimens  over  each  other.  Place  another  sheet 
of  newspaper  over  the  lichens,  followed  by  one  or  two 
dryers,  then  begin  with    the  arrangement  of  another 


LICHENS    AND    THE    NATURALIST.  67 

layer  of  lichens,  and  continue  this  process  until  the 
entire  collection  of  fruticose  and  foliose  lichens  is 
placed  between  dryers.  On  top  of  the  entire  pile 
place  a  board  with  a  weight  of  from  20  to  25  pounds.  ^ 
For  the  first  two  days  the  specimens  with  the  two 
sheets  of  newspaper  should  be  transferred  to  dry  dryers 
twice  daily.  For  this  purpose  it  is  necessary  to  have 
two  sets  of  dryers  ;  the  moist  ones  should  be  exposed 
to  the  sun  while  the  others  are  in  use.  For  the  next 
three  days  they  need  be  changed  only  once  daily.  At  - 
the  end  of  five  days  the  lichens  are,  no  doubt,  perfectly 
dry;  they  will  be  found  permanently  flattened  and 
ready  for  mounting. 

Lichens,  like  all  other  botanical  specimens,  should 
be  mounted  on  the  regulation  mounting  sheets  of  • 
heavy  glazed  white  paper.  Fasten  the  specimens  to 
the  paper  by  means  of  glue  (fish-glue).  Arrange  the 
specimens  uniformily,  but  never  place  more  than  one 
species  on  a  sheet.  With  foliose  lichens,  it  is  desirable 
to  place  two  specimens  side  by  side,  one  showing  the  .  - 
lower  surface  and  the  other  the  upper  surface.  If  the 
specimens  are  large,  one  will  be  enough  to  place  on  a 
sheet ;  if  small,  as  many  as  five  or  six  may  be  glued  on. 
In  this  case  it  is  advisable  to  select  specimens  from 
widely  different  latitudes  and  altitudes. 

As  soon  as  the  specimens  are  glued  on  the  sheets 
they  should   again  be  placed  between  the  sheets  of    .    ^ 
newspaper  and  dryers,  with  pressure  applied  until  the 
glue  is  perfectly  dry,  when  they  are  ready  to  be  placed 
in  the  herbarium  with  other  specimens. 

If  mounting  paper  is  not  at  hand,  the  specimen  may 


68  GUIDE    TO    THE    STUDY    OF    LICHENS. 

be  glued  in  a  scrap-book  or  a  blank  book  of  a  similar 
nature.  In  this  case  it  is  advised  to  follow  some  system ; 
that  is,  place  the  specimens  belonging  to  the  same  genus 
on  successive  pages  and  arrange  the  genera  in  the  order 
they  are  given  in  the  guide.  If  one  scrap-book  is  filled, 
get  another  of  the  same  kind  and  proceed  as  before. 
For  the  amateur  the  scrap-book  method  will  prove 
most  satisfactory ;  but  if  it  is  intended  to  accumulate 
an  extensive  or  approximately  complete  collection,  it 
is  advisable  to  use  the  mounting  sheets. 

The  specimens  may  also  be  glued  on  small  pieces  of 
heavy  paper  (bristol-board  will  answer  very  well). 
/  '  Later  these  sheets  with  the  specimens  may  be  glued 
on  the  regulation  mounting  paper,  or  in  the  scrap-book. 
In  all  instances  space  should  be  left  to  paste  the  label 
at  the  lower  right-hand  corner, 

Crustose  bark-lichens  and  the  smaller  specimens  of 
crustose  rock-lichens  may  be  mounted  at  once.  Re- 
move unnecessary  bark  and  rock,  and  make  them  as 
presentable  as  possible  before  mounting.  Usually, 
rock-specimens  are  too  heavy  to  be  mounted  on  paper; 
they  had  best  be  kept  in  small  pasteboard  boxes,  or 
in  the  paper  pockets  about  to  be  described.  In  any 
case  it  is  not  at  all  likely  that  the  beginner  will  care 
to  make  an  extensive  collection  of  rock-specimens. 

Lichens  may  also  be  put  up  in  paper  pockets,  especially 
those  intended  for  exchange.  A  paper  pocket  is  noth- 
ing more  or  less  than  a  piece  of  heavy  paper  (manila 
or  similar  paper)  folded  in  such  a  manner  as  to  hold 
the  specimen.  They  may  be  made  as  follows  :  Secure 
the  right  sort  of  paper,  and  cut  or  have  it  cut  into 


LICHENS    AND    THE    NATURALIST.  69 

suitable  sizes.  Take  one  of  the  rectangular  pieces 
and  fold  it  from  the  bottom  to  within  an  inch  of  the 
top  ;  turn  down  the  top  one  incli,  so  that  the  upper 
flap  folds  over  the  lower  flap  ;  now  turn  the  sides  under 
(or  back)  for  a  space  of  one  inch,  crease  the  edges 
well  and  the  pocket  is  complete.  It  will,  of  course, 
be  necessary  to  have  assorted  sizes  of  pockets,  to  suit 
the  sizes  of  the  different  specimens  ;  but  do  not  make 
too  many  different  sizes,  three  will,  perhaps,  be  enough 
for  all  practical  purposes.  These  pockets,  with  the 
specimens,  may  be  glued  on  the  mounting  sheets  or  in 
the  scrap-book  ;  in  which  case  the  label  is  pasted  on 
the  outside  of  the  lower  flap.  If  the  specimens  are  in- 
tended for  exchange  the  labels  should  be  placed  on  the 
inside  with  the  specimen  and  not  glued,  so  as  not  to 
inconvenience  the  one  with  whom  you  are  making  ex- 
changes, should  he  desire  not  to  mount  them  with  the 
pockets.  It  must  also  be  remembered  that  many  crus- 
tose  soil-lichens  and  some  of  the  smaller  fruticose 
forms  can  only  be  kept  in  pockets  or  boxes.  There 
are  also  other  styles  of  pockets  than  the  one  here  de- 
scribed ;  perhaps  the  reader  will  invent  a  better  and 
more  convenient  form. 

Every  specimen  should  be  labelled ;  in  fact,  a  speci- 
men without  a  label  is  of  little  value  from  a  botanical 
point  of  view.  The  label  ghould  be  of  sufficient  size 
for  the  following  data :  Name,  where  collected  (give  a 
recognizable  geographical  locality),  elevation,  date 
when  collected,  and  the  name  of  the  collector.  Labels 
should  either  be  printed,  or  written  with  pen  and  ink. 
If  labels  are  not  at  hand  write  the  above  items  on  the 


70  GUIDE    TO    THE    STUDY    OF    LICHENS. 

sheet  or  pocket ;  even  if  the  name  of  the  specimen  is 
not  known,  do  not  fail  to  give  the  other  data. 

In  conclusion,  the  following  general  advice  may  be 
found  useful.  Put  up  only  good  large  specimens ; 
scrawny,  small  specimens  are  not  desirable  unless 
they  are  the  only  kind  obtainable  in  the  locality. 
Mount  a  goodly  number  of  duplicate  specimens  for  the 
purpose  of  making  exchanges.  Make  your  exchanges 
with  a  view  to  mutual  gain  ;  to  do  this,  it  is  necessary 
to  make  exchanges  with  parties  in  widely  different 
localities  ;  state  what  you  have  and  ask  for  what  you 
would  like  in  exchange. 

For  mounting  sheets,  driers,  labels,  vasculums,  in 
fact  anything  desirable  in  a  botanical  line,  enter  into 
communication  with  some  dealer  in  botanical  supplies. 
Purchase  only  what  is  needed  ;  use  home  material  as 
much  as  possible. 


PART  II 

SYSTEMATIC   STUDY  OF  LICHENS 


SYSTEMS    OF    CLASSIFICATION.  73 


SECTION  I. 

SYSTEMS   OF   CLASSIFICATION. 

In  a  general  way  it  may  be  stated  that  one  of  the 
ultimate  aims  of  science  is  to  classify.  It  must  not  be 
supposed,  however,  that  the  mere  naming  and  arrang- 
ing of  things  is  in  itoelf  the  object  in  view.  It  is  sim- 
ply the  means  to  an  end ;  classification  simplifies  the 
work  for  those  who  follow  :  it,  so  to  speak,  represents 
the  status  of  the  science  under  consideration. 

One  of  the  most  common  errors  that  amateur  scien- 
tists fall  into  is  to  suppose  that  a  given  system,  we  will 
say  of  a  group  of  plants,  is  something  fixed  and  abso-^ 
lutely  reliable.  This  is  by  no  meaiis  the  case;  every 
system,  no  matter  how  elaborate  it  may  seem  or  by 
whom  it  may  be  proposed,  is  imperfect  and  subject  to 
change  as  new  discoveries  are  made.  This,  however, 
does  not  imply  that  the  existing  systems  are  useless. 
They  are  of  inestimable  value  in  so  far  as  they  repre- 
sent the  most  reliable  facts  obtained  in  regard  to  the 
science  under  consideration.  As  soon  as  a  system  fails 
to  be  in  harmony  with  the  most  advanced  and  reliable 
investigations  it  will  of  necessity  make  way  for  a  bet- 
ter system. 

Two  kinds  of  systems  are  usually  recognized  :  one  is 
known  as  the  "  artificial  system,"  the  other  as  the 
"  natural  system."     In  the  former  no  attempt  is  made 


74  GUIDE    TO    THE    STUDY    OF    LICHENS. 

to  show  the  natural  relationship  of  the  organisms, 
while  in  the  latter  an  attempt  is  made  to  show  the 
affinities  of  families,  genera  and  species.  If,  for  in- 
stance, all  flowering  plants  are  classified  according  to 
the  differences  in  the  leaves,  we  have  a  purely  artificial 
system  ;  in  such  a  system  it  would  be  necessary  to 
place  together  plants  which  have  no  close  relationship  ; 
and,  again,  it  would  be  necessary  to  separate  others 
which  are  undoubtedly  closely  related.  In  the  so-called 
natural  system  all  the  known  characters  are  employed. 
In  the  case,  for  example,  of  the  flowering  plants,  not 
only  the  leaf  characters,  but  also  those  of  the  flowers, 
the  seed,  the  stem,  the  histological  and  physiological 
differences,  etc. 

If  we  stop  to  consider,  we  find  that  the  natural  sys- 
tem is,  in  a  degree,  also  artificial,  for  the  simple  reason 
that  all  of  the  facts  regarding  morphology  and  physiol- 
ogy, evolution,  etc,  are  not  yet  known,  and,  so  far  as 
we  know  at  present,  never  will  all  be  known.  Human 
knowledge  is  finite ;  it  is,  so  to  speak,  hemmed  in  on 
all  sides  ;  what  little  we  do  recognize  as  "facts"  has 
for  its  basis  something  which  is  taken  for  granted,  and 
of  which  we  therefore  know  nothing. 

As  regards  the  classification  of  lichens,  it  may  be 
stated  that  a  natural  system  is  practically  non-existent. 
Only  within  a  few  years  have  any  efforts  been  made  to 
show  the  natural  affinities  of  the  different  lichens  and 
lichen-groups.  Heretofore,  nearly  every  specialist  on 
lichenology  had  proposed  a  new  system,  thus  adding  to 
the  existing  confusion.  We  now  know  that  a  lichen 
is  a  morphological  unit,  which  resulted  from  the  sym- 


SYSTEMS    OF    CLASSIFICATION.  75 

biotic  association  of  a  fungus  and  an  alga.  Lichens, 
therefore,  have  a  double  affinity,  being  closely  related 
to  the  fungi  on  the  one  hand  and  to  alga^  on  the  other. 
Their  true  position  is  between  the  fungi  and  algae. 
They  are  a  class  of  the  cryptogaraic  (flowerless)  plants 
devoid  of  stem  and  leaves.  We  have  already  discussed 
some  of  the  structures  of  lichens  which  are  analoirous  to 
certain  structures  of  higher  plants.  This  analogy  does 
not  indicate  any  close  natural  relationship.  Lichens 
have  no  roots,  leaves,  branches,  vascular  tissue,  epi- 
dermis, etc.,  as  we  find  them  in  higher  plants ;  the 
analogies  are  indeed  very  remote. 

The  present  tendency  in  classification  is  to  proceed 
from  the  lowest  to  the  highest,  from  the  less  special- 
ized to  the  more  specialized,  rather  than  from  the 
highest  to  the  lowest.  This  is  the  natural  way,  as  by 
this  method  one  can  better  explain  the  characters 
which  indicate  their  relationship. 

Since  lichens  are  treated  as  a  distinct  class  and  not 
as  fungi,  the  effort  must  be  made  to  show  their  rela- 
tionship to  each  other ;  in  order  to  do  this,  we  must 
also  study  their  relationship  to  the  fungi  by  endeavoring 
to  find  their  probable  fungal  ancestors.  Such  attempts 
have  recently  been  made  by  Reinke  and  others,  but 
much  remains  yet  to  be  done. 

The  amateur  need  not  worry  about  the  imperfections 
indicated ;  the  systems  at  hand  will  suffice  for  the 
present ;  future  generations  will  work  with  other  sys- 
tems. 


76  GUIDE    TO    THE    STUDY    OF    LICHENS. 

SECTION  11. 
KEYS  TO  THE  STUDY   OF  LICHENS. 

Keys  to  a  system  of  plants  are  of  value,  but  this 
value  is  generally  overestimated  The  usefulness  of  a 
key  depends  largely  upon  the  one  who  makes  it ;  if 
he  has  a  thorough  knowledge  of  the  subject,  he  is 
generally  able  to  construct  a  key  which  will  be  found 
highly  useful  by  others.  Any  key,  whether  natural  or 
artificial,  should  contain  the  fewest  words  possible 
consistent  with  clearness  ;  close  attention  must  also  be 
given  to  co-ordination  and  subordination. 

Two  keys  are  here  proposed :  one,  the  artificial,  in- 
tended for  those  who  cannot  secure  the  use  of  a  com- 
pound microscope,  and  who  are  dependent  upon  the 
eye  and  a  pocket-lens  to  aid  them  ;  the  second,  a  nat- 
ural key,  recommended  to  those  who  have  a  compound 
microscope  at  their  disposal. 

It  will  be  noticed  that  in  the  artificial  key  the  thal- 
lus  and  apothecia  are  of  prime  importance ;  in  the 
natural  key  the  algae  and  spores  are  of  first  importance 
in  the  determination  of  genera.  No  attempt  has  been 
made  to  arrange  keys  to  the  species. 

In  the  artificial  key  it  was  found  necessary  to  com- 
bine several  genera  in  some  instances,  because  no  marked 
macroscopic  differential  characters  were  noticeable. 
Furthermore,  several  insignificant  genera  have  been 
wholly  omitted. 


KEYS    TO    THE    STUDY    OF    LICHENS.  77 

I.     ARTIFICAL  KEY  TO  THE  MORE  IMPORTANT  GENERA 
OF  LICHENS  OCCURRING  IN  THE  UNITED  STATES. 

Thallus  Crcstose. 

Stipes  present  with  terminal  apothecia,  plants  small. 
Stipes  and  apothecia  black. 
Apothecia  somewhat  flattened  (discoid)  .    .       Cyphelium. 

Apothecia  globose  (spherical) Calicium. 

Stipes  light  colored. 
Apothecia  small,  brownish,  bark-lichens      .    .  Coniocybe. 
Apothecia  large,  earth-lichens Bceomyces. 

Stipes  wanting,  apothecia  more  or  less  immersed. 
Apothecia  distinctly  linear. 

Length  of  apothecia  usually  exceeding  four  times  their 

width ;  black  or  white Graphis. 

Length  of  apothecia  usually  not  exceeding  four  times 
their  width  ;  black. 

On  decaying  wood Xi/lographa. 

On  bark  of  trees Opegrapha. 

Apothecia  not  linear,  irregular. 

Oval  or  oblong Hazslinskya. 

Irregular,  not  oval  or  oblong. 
Disk  distinctly  visible,  black. 

Apothecia  small Arthonia. 

Apothecia  comparatively  large    .     .     .  Arthothelium 
Disk  indistinct,  mostly  immersed    .     .     .    Mycoporum. 

Apothecia  regular  in  outline. 
Immersed  in  thallus  or  substratum  ;  globose. 
Not  in  colonies. 

Disk  light  colored Pertusaria. 

Disk  black  or  dark. 

Occurring  on  rocks Verrucaria. 

Occurring  on  bark 
Apothecia  almost  entirely  covered 

by  substratum Pyrenula. 

Apothecia  more  elevated,  urn- 
shaped Gyrostomum. 

Apothecia  crateriform Thelolrema. 

In  colonies Trypethelium. 

Immersed  in  thallus  ;  not  globose. 

Disk  not  projecting  above  surface  of  tliallus. 

Thallus  light-gray Urreolaria. 

Thallus  dark Acarospora. 

Disk  projecting  above  the  green  thallus  .     .     Acolium. 


78  GUIDE    TO    THE    STUDY    OF    LICHENS. 


Hypothecium  black  ^ -J 


Apothecia  discoid  or  semiglobose ;  sessile,  not  immersed. 
Disk  black  or  dark. 

Bacidia. 
Lecidea. 

i  Biatora. 

Hypothecium  colorless )  Bilimhia. 

(  Lecanora. 

Disk  orange  to  rusty-red Placodium. 

Thallus  Foliose. 

Thallus  entire  or  lobes  plicate,  grayish-brown  or  dark. 
Apothecia  innate  or  immersed. 
Apothecia  comparatively  large ;  innate  in  depressions 

of  the  thallus Heppia. 

Apothecia  small,  immersed. 
Thallus  simple,  very  minute,  adnate,  .    Dermatocarpon. 
Thallus  about  five  mm.  in  diameter,  not 

closely  adnate Psora. 

Thallus  large,  umbilicate Endocarpon. 

Apothecia  sessile,  black ;  thallus  large,  umbilicate, 

Thallus  pustular Umbilicaria. 

Thallus  not  pustular Gyrophora. 

Thallus  distinctly  lobed  or  branching,  usually  large. 
Apothecia  cup-shaped  or  discoid,  sessile. 
Cyphellae  present.2 
Thallus  blue-green  to  dark-brown,  soredia 

yellow Stictina. 

Thallus  greenish  to  light-brown,  soredia 

not  yellow Sticta. 

Cyphallae  wanting. 
Thallus  ash-gray,  comparatively  small. 
Branching  distinct,  lobes  of  uniform 

width Speerschneidera. 

Branching  less  distinct,  lobes  not  of 

uniform  width Physcia. 

Branching     indistinct,    thallus     thin, 

closely  adnate Pyxine. 

Thallus  greenish,  more  rarely  brown  to 

dark,  large Parmelia. 

Thallus  brown,  small,  closely  adnate  .     .     .   Pannaria. 

*  Make  a  vertical  section  through  the  apothecium  and  examine 
with  a  good  pocket  lens. 

*  Sticta  amplissima  and  S.  pidmonaria  are  devoid  of  cyphellae. 


KEYS  TO  THE  STUDY  OF  LICHENS.       79 


Tliallus  distinctly  blue-green  to  dark-blue, 
thin,  higlily  gelatinous  when  moist. 

Lower  surface  devoid  of  long  rhizoids,     |  CoUema. 
Lower   surface    bearing  long  rhizoids, 

thallus  comparatively  thick      ....  Mallotium. 

Lower  surface  veined Hydrothyria. 

Apothecia  innate,  not  cup-shaped. 

On  lower  surface  of  upturned  lobes    .     .     .  Nephromium. 
On  upper  surface  of  thallus. 
Thallus  comparatively  small,  apothecia 

not  marginal Solorina. 

Thallus  large,  apothecia  marginal  ....    Peltigera. 

Thallus  Fruticose. 

Thallus   very  minute,   dark-blue,   scarcely  visible  to   the 
naked  eye. 
Apothecia  terminal,  more  or  less  globose. 

Thallus-lobes  distinctly  flattened    ....     Omphalaria. 
Thallus-lobcs  not  distinctly  flattened  ....      Lichina. 

Apothecia  lateral,  discoid Poiychidium. 

Apothecia  within  thallus Ephebe. 

Thallus  distinct  to  very  large. 

Yellowish  coloration  in  thallus  or  apothecia. 

Thallus  distinctly  flattened Theloschistes. 

Thallus  not  distinctly  flattened Evernia. 

Yellowish  coloration  wanting. 

Thallus  flattened,  thick,  not  brown  or  dark. 

Disk  black,  thallus  gray  to  purplish   .     .     .       Rocella. 

Disk  not  black,  thallus  greenish Ramalina. 

Thallus  flattened,  thin,  brown  to  dark    .     .     .      Cetraria. 
Thallus  cylindrical,  hollow. 
Apothecia  terminal. 

Disk  black PiJophoron. 

Disk  brown  or  red Chdonia. 

Thallus  cylindrical,  solid. 
Branches  long,  pendulous. 

Color  green  to  grayish-green Usnea. 

C  Bryopoqon. 
Color  dark  to  black <  Alector'ia. 

Branches  rigid,  erect. 

Smooth,  shiny Sphcerophoi-us. 

Not  smooth,  warty Stereocaulon. 


80  GUIDE    TO    THE    STUDY    OF    LICHENS. 

II.       NATURAL    KEY    TO    THE    FAMILIES. 

The  natural  keys  to  the  genera  are  given  after  the 
description  of  the  families.  In  the  use  of  the  natural 
key  to  the  families  and  genera,  the  beginner  is  depend- 
ent upon  the  use  of  the  compound  microscope.  The 
student  is  advised  to  keep  in  mind  the  suggestions 
given  in  the  chapter  on  "  The  Study  of  Lichens." 

KEY. 

Algae  of  the  thallus  bright-green. 
Fungal  type  of  apothecium. 

Apothecia  terminal  on  stipes  or  on  the  f  ruticose  thallus. 
Disk  closed,  finally  opening  by  a  terminal  pore  or 
crevice /.  CALJCIACEjE. 

Disk  open,  convex,  light-brown  or  red, 

//,  CLADONIACEjE. 

Apothecia  sessile  on  the  crustose  or  foliose  thallus. 
Disk  cup-shaped,  flattened  or  convex,  brown  or  black, 

///.  LECIDEACE^. 

Apothecia  linear,  irregular  or  stellate ;  thallus  crus- 
tose     IV.  GRAPHIDACE^, 

Thalline  type  of  apothecium  or  apothecia  immersed  in 
the  thallus. 
Apothecia  discoid  and  sessile,  rarely  immersed. 

Plasmic  masses  of  spores  united,  spores  two-celled, 

r.  PHTSCIACEuE. 

Plasmic  masses  of  spores  not  united, 

VI.  PARMELIACE^. 

Apothecia  immersed  in  the  substratum  or  thallus, 

opening  by  a  minute  pore,    VII.  VERRUCARIACEM. 
Algae  of  the  thallus  blue-green.^ 

Thallus  foliose,  dark-blue,  gelatinous  when  moist, 

VIII.     COLLEMACEJS. 

Thallus  minutely  fruticose  or  foliose,  not  gelatinous  when 

moist IX.  PANNARIACEjE. 

The  descriptions  of  the  families  and  genera  will  be 
made  as  brief  as  possible.     Those  who  wish  to  study 

1  The  following  genera  of  the  Pannariaceae  ha.ve  bright-green  algse; 
Nephroma,  Solorina,  Sticta  and  Psoroma, 


GENERA    ANt)    SPECIES.  81 

the  affinities  of  the  various  groups  are  referred  to  more 
complete  works  on  the  subject.  It  is  intended  to  devote 
most  attention  to  the  description  of  the  species,  dwell- 
ing particularly  ui)on  the  points  of  liistorical  interest, 
thus  rendering  the  subject  less  dry  and  monotonous. 

An  attempt  has  been  made  to  arrange  the  genera  and 
species  in  a  natural  order  beginning  with  the  lowest. 

/.     CALICIACE^. 

With  comparatively  few  exceptions,  the  representa- 
tives of  this  family  are  insignificant  in  appearance. 
The  thallus  is  either  crustose  or  fruticose.  The 
apothecia  are  globose  and  terminal  upon  the  stipes 
or  on  the  branches  of  the  fruticose  thallus.  A  stipe  is 
a  small,  simple,  erect  stalk  devoid  of  algae,  hence  is  not 
a  part  of  the  thallus  ;  it  is  an  apothecial  stalk  bearing 
the  apothecia. 

Upon  an  examination  of  the  Caliciaceae,  it  will  be 
found  that  the  spore-sacs  dissolve  and  set  free  the  im- 
mature spores  which  lie  above  the  thecium  and  are 
covered  over  by  the  exciple  (proper  exciple).  Finally, 
there  is  a  rupture  of  the  apical  portion  of  the  apothe- 
cium,  setting  free  the  spores. 

None  of  the  representatives  of  this  family  have  any 
special  historical  interest. 

KEY  TO  THE   GENERA. 

Thallus  crustose. 
Apothecia  terminal  on  slender  stipes. 

Spores  simple,  colorless 1.  Coniocyhe. 

Spores  two-celled,  dark 2.   Calicium. 

Spores  simple,  dark 3.   Ci/p/ielium. 

Apothecia  sessile  ;  spores  two-celled,  dark,  4-  Acolium. 
Tliailus  rigidly  fruticose,  terniiual  apothecia,  5.  Splui^rophorus. 


82  GUIDE    TO    THE    STUDY    OF    LICHENS. 

1.    Coniocyhe} 

The  representatives  of  this  genus  are  few  and  insig- 
nificant; close  examination  is  necessary  to  detect 
them.  Usually,  they  occur  upon  the  bark  of  trees  in 
shaded  places ;  less  commonly  upon  decaying  wood. 
The  thallus  is  generally  visible  to  the  naked  eye,  and 
has  a  yellowish  tinge.  The  apothecia  and  stipes  are 
of  a  light  color,  never  black  ;  however,  the  color  is 
quite  variable,  ranging  from  almost  white  to  brownish- 
gray  and  reddish-brown.  The  alg^e  seem  to  belong  to 
the  genus  Chroolepus  and,  therefore,  occur  in  chains. 
The  spores  are  spherical,  small,  simple,  colorless,  or 
faintly  yellowish,  with  a  distinct,  irregular  exosporium, 
which  is  readily  removed,  T/x  to  8/x.^ 

Coniocyhe  pallida  is  the  only  species  which  is  likely 
to  be  found.  Coniocyhe  furfur acea  is  usually  sterile, 
that  is,  devoid  of  stipes  and  apothecia. 

1.  Coniocyhe  pallida.  Thallus  usually  indistinct, 
whitish.  Stipes  comparatively  long  and  slender,  from 
nearly  white  to  brown,  bearing  single  globose  apo- 
thecia of  nearly  the  same  color  as  the  stipe.  Spores 
simple,  colorless,  exosporium  quite  distinct,  1  fx.  to  8/x. 
On  bark.  New  England  (New  Hampshire),  Iowa. 

2.  Coniocyhe  furfuracea.  Thallus  quite  distinct,  of 
a  sulphur  color.  Stipes,  apothecia  and  spores  as  in 
C.  pallida.  On  the  exposed  roots  of  trees  and  decay- 
ing wood.  New  England,  New  York.    Sterile  in  Iowa. 

1  The  spores  of  all  the  genera  mentioned  are  figured  on  Plates  V  to 
XI  inclusive.    The  genera  are  given  alphabetically. 

2  A  /(i  or  micron  equals  a  thousandth  of  one  millimeter  or  one 
twenty-five-thousandth  of  an  inch.  The  measurements  are  made 
with  the  aid  of  an  eye-piece  micrometer. 


GENERA    AND    SPECIES.  83 

2.  Calicium. 
This  genus  is  represented  by  a  considerable  number 
of  species,  which  are  uniformly  insignificant  plants, 
having  no  special  interest  for  the  amateur.  In  form 
they  resemble  Coniocybe.  The  stipes  and  apothecia 
are  black,  in  other  respects  like  those  of  Coniocybe, 
They  occur  upon  tree  trunks  in  shaded  places,  upon 
fences  and  decaying  wood.  The  algae  are  Protococus 
viridis ;  they  occur  singly,  and  are  of  a  bright-green 
color.  In  some  species  the  thallus  is  very  deficient, 
or  even  wholly  wanting,  particularly  in  older  speci- 
mens. Some  species  are  included  among  fungi 
(Mucor)  by  various  authors. 

Tiie  spores  are  two-celled  and  dark. 

1.  Calicium  Curtisii.  Tliallus  wanting,  or  very 
rudimentary.  Stipes  dark,  slender,  bearing  a  single, 
dark,  globose  apothecium.  Spores  brown,  two-celled, 
oblong,  with  pointed  ends,  14/x  X  5/x. 

Occurs  on  tree-trunks,  especially  species  of  Hhus. 

2.  Calicium  fuscipes.  Thallus  rarely  recognizable. 
Stipes  rather  long  and  slender,  dark-brown.  Apo- 
thecia spherical,  dark-brown  ;  in  fully  matured  plants 
the  entire  thecium  may  fall  away.  Spores  dark-brown, 
elliptical,  simple,  12/x  X  5.5/x. 

3.  Calicium  lenticulare.  Thallus  indistinct,  color- 
less or  whitish.  Stipes  rather  short  and  thick.  Apo- 
thecia comparatively  large  and  somewhat  flattened. 
Spores  small,  dark-brown,  elliptical,  simple,  6.0/x  X  4^. 

4.  Calicium  hyperellum.  Thallus  only  slightly  de- 
veloped, greenish-yellow,  unevenly  spreading.  Stipes 
long,  slender,  dark-brown.     Apothecia  usually  spheri- 


84  GUIDE    TO    THE    STUDY    OP   LICHENS. 

cal,  dark-brown  or  rusty-brown.  Spores  brown,  ellip- 
tical, two-celled,  somewhat  constricted  in  the  middle, 
10/x  X  6/x. 

5.  Calicium  quercinum.  Thallus  much  as  in  C. 
hyperellum,  less  highly  developed,  not  greenish-yellow. 
Stipe  less  slender,  dark-brown.  Apothecia  usually 
spherical,  dark-brown.  The  entire  structure,  includ- 
ing spores,  resembling  that  of  C.  hyperellum.  Spores 
brown,  two-celled,  constricted  in  the  middle,  10/x  X  ^yu,. 

3.   Gyphelium. 

The  representatives  of  this  genus  have  the  general 
characters  of  the  Calicii.  The  apothecia  are  some- 
what flattened  and  the  spores  are  simple  and  dark, 
thus  contrasting  them  with  those  of  Coniocyhe  and 
Calicium,  the  exosporium  is  generally  considerably 
thickened.  In  form  they  are  usually  spherical  though 
they  may  be  elliptical.  The  alg^e  are  as  in  Calicium. 
In  fact  the  amateur  will  perhaps  place  the  speci- 
mens with  the  Calicii  owing  to  their  great  similarity. 
They  occur  in  the  same  localities  as  the  other  Cali- 
ciaceae. 

1.  Cyphelium  turhinatum.  Thallus  crustose,  well 
developed.  Stipe  very  short,  projecting  slightly 
above  the  lobes  of  the  thallus.  Apothecium  much 
as  in  the  foregoing,  dark-brown,  entirely  closed  at 
first,  later  opening  by  Cep-segment.  Spores  small, 
dark  brown,  spherical,  simple,  exine  considerably 
thickened,  7.5/x,  X  6.5/a. 

2.  Cyphelium  tuhoBforme.  Thallus  occurs  almost 
entirely   under    the   bark,    fairly   developed.      Stipe 


GENERA    AND    SPECIES.  85 

rather  short,  of  medium  thickness,  dark.  Apothecia 
somewhat  flattened,  dark.  Spores  rather  large,  sim- 
ple, dark-brown;  usually  spherical;  some  slightly 
elongated  with  pointed  tips,  exine  distinct,  12/x  X  20/a. 

Jf..  Acolium. 
This  genus  is  undoubtedly  closely  related  to  Calu 
cium.  The  thallus  is  well  developed  and  of  a  marked 
green  color  in  A.  tigillare.  The  stipe  is  much  re- 
duced, so  that  the  apothecium  is  sessile  or  immersed 
in  the  thallus.  The  thallus  encloses  the  apothecium 
in  a  crater-like  fashion,  showing  the  dark  epithecium 
at  the  top.  The  spores  are  two-celled  and  dark. 
The  algas  are  as  in  CaUcium. 

There  are  only  two  species  reported  in  the  United 
States,  of  which  A.  tigillare  is  quite  common.  Its 
natural  substratum  seems  to  be  old  pine  fence-boards, 
upon  which  it  occurs  in  patches  of  considerable  extent. 
From  its  position  it  is  evident  that  it  has  the  ability 
to  resist  greater  extremes  of  dryness  than  the  major- 
ity of  lichens.  It  occurs  quite  frequently  on  fence- 
boards  in  prairie  farm-yards  which  are  comparatively 
little  shaded. 

1.  Acolium  tigillare.  Thallus  distinctly  crustose 
and  minutely  areolate,  yellowish-green.  Apothecia 
numerous;  the  very  short  stipes,  as  well  as  the 
greater  portion  of  the  apothecium,  are  enclosed  by 
the  thallus,  producing  conical  elevations.  Epithecium 
dark.  Spores  two-celled,  somewhat  constricted  at  the 
middle,  thick,  dark  spore-wall,  10/x  X  14/x. 


86  OmDE   TO    THE    STUDY    OF    LICHENS. 

5.  Sphcerophorus. 

This  genus  represents  the  highest  development  .of 
the  Caliciaceae,  there  is  a  wide  gap  between  it  and 
Acolium.  The  links  are  entirely  wanting  in  the 
United  States.  It  has  been  questioned  whether 
Sphaerophorus  belongs  to  the  Caliciaceae  ;  concerning 
this  there  can,  however,  be  no  doubt.  The  apothecia 
and  spore  characters  are  the  same  as  those  of  the  other 
genera. 

The  thallus  is  fruticose,  quite  large,  of  a  rigid  car- 
tilaginous consistency  ;  color  brown  or  reddish-brown. 
The  apothecia  are  globose  and  terminal  on  the  branches 
of  the  thallus  ;  they  open  by  terminal  chinks,  thus  set- 
ting free  the  simple  dark  spores.  The  spores  are  char- 
acterized by  the  irregular  dark  blue  exine  (exosporium) 
which  is  readily  removed. 

1.  Sphcerophorus  fragilis.  Thallus-lobes  cylin- 
drical, smooth,  color  somewhat  variable,  from  light 
gray,  brownish  to  dark,  dichotomously  branching,  ends 
of  branches  usually  with  numerous  short  lobes,  tips 
blunt  or  rounded.  Usually  sterile  or  apothecia  few, 
shrunken.  Disk  black.  Entire  apothecium  easily  re- 
moved at  the  hypothecial  zone.  Spores  elliptical, 
simple,  dark-brown  exine,  15/x  X  10/>i- 

2.  Sphcerophorus  glohiferous.  Thallus  lobes  cylin- 
drical, variable  in  length,  usually  of  uniform  brown 
color,  especially  in  old  herbarium  material.  Branch- 
ing dichotomous.  Apothecia  globoid,  opening  by 
chinks  or  pores.  Spores  spherical,  simple,  blue-black 
exine  easily  removed  by  pressure,  12/x  X  IV* 


GENERA    AND    SPECIES.  87 

77.    CLADONIACE^. 

The  representatives  of  this  family  are  quite  common 
everywhere,  occurring  chiefly  upon  soil  or  rocky 
ledges  ;  less  commonly  upon  old  fences,  tree-trunks  and 
rotten  wood.  They  are  conspicuous  as  to  size.  The 
thallus  is  peculiar  in  that  it  is  made  up  of  two  parts: 
one  erect  (secondary  thallus  or  podetium,  hence  fruti- 
cose),  varies  from  simple  to  much  branched  ;  the  other 
portion  (primary  thallus),  spreading  over  the  substra- 
tum, varies  from  crustose  {Bceomyces)  to  foliose  {Cla- 
donid).  Strictly  speaking,  the  upright  portion  of 
Bceomyces  is  only  a  stipe,  as  in  the  preceding  family. 

The  apothecia  are  distinct  and  occur  in  all  the 
genera  excepting  ThamnoUa,  which  is  always  sterile. 
They  are  more  or  less  globose,  disk  convex  to  flat- 
tened but  never  cup-shaped.  No  alg£e  occur  in  any 
part  of  the  apothecia ;  for  that  reason  they  belong  to 
the  fungal  type.     (See  Figs.  1  and  2,  Plate  IV.) 

KEY  TO   THE  GENERA. 

Thallus  (primary)  crustose  or  warty. 
Apothecia  borne  on  unbranched  thick  stipes  or  nearly 

sessile 1.  Bceomyces. 

Apothecia  terminal  on  the  erect  tliallus  (podetia). 

Erect  thallus  hollow,  spores  simple     .     .    2.  Pilophoron. 
Erect  thallus  solid,  spores  four-celled      .    3.  Stereonndon. 
Thallus  (primary)  foliose  or  wantinfj,  erect  thallus  hollow. 
Apothecia  usually  present,  disk  brown  or  red, 

4-   Cladonia. 
Apothecia  always  wanting,  erect  thallus  tapering, 

5.  Thamnolia. 
1.   Bceomyces. 

The  representatives  of  this  genus  usually  occur 
upon  loamy  or  sandy  soil  in  forest  lands.  Tlie  primary 
thallus  is  usually  crustose ;  in  some  of  the  Southern 


88  GUIDE    TO    THE    STUDY    OF    LICHENS. 

forms  it,  however,  becomes  almost  foliose.  The  name 
Bceomyces  meaus  a  "  small  fungus,"  or  "  toadstool." 
The  light  color  of  the  stipes  and  apothecia  do  give  it  a 
marked  resemblance  to  the  fungi  of  the  mushroom  or 
toadstool  order.  The  stipes  are  never  branching,  and 
are  almost  entirely  wanting  in  one  species.  The  apo- 
thecia are  well  developed  and  vary  from  globose  to  dis- 
tinctly flattened.  The  algae  are  light-green,  single- 
celled,  belonging  to  Protococcus.  A  Glceocapsa  also 
occurs  with  some  species  (^B.  roseus).  Spores  are  col- 
orless, spindle-shaped  to  almost  acicular,  simple  or 
very  indistinctly  septate. 

None  of  the  species  have  been  credited  with  any 
special  virtues. 

The  collector  will  meet  with  these  plants  in  forest 
lands,  where  they  occur  in  patches,  usually  several  feet 
(sometimes  less)  in  diameter.  B.  roseus  is  most  com- 
mon, and  is  characterized  by  a  greenish-gray  crustose 
thallus,  which  is  in  marked  contrast  with  the  soil. 
Care  is  necessary  to  preserve  the  specimen.  Place  the 
lichens,  attached  to  a  considerable  portion  of  the  soil, 
in  a  suitable  pasteboard  box,  or  wrap  carefully  in  pa- 
per. They  had  best  be  kept  in  paper  pockets  or  in 
small  pasteboard  boxes,  as  indicated. 

1.  Bceomyces  roseus.  Thallus  granulose,  greenish. 
Stipes  comparatively  long,  white  or  a  faint  rosy  tint. 
Apothecia,  spherical  (both  stipe  and  apothecium  col- 
lapse on  drying).  Disk  a  rosy  tint.  Spores  in  long 
slender  sacs,  acicular,  usually  slightly  curved,  some- 
times faintly  septate,  colorless,  25.5/a  X  3.5/i. 


GENERA    AND    SPECIES.  89 

2.  BcBomyces  ceruginosus.  Thallus  evenly  spread- 
ing, with  rather  large  granules,  gray-green.  Stipes 
very  short  or  none.  Apothecia  quite  flat,  yellowish 
disk.  Spore-sacs  long,  cylindrical ;  spores  oblong,  col- 
orless, usually  distinctly  uniseptate,  17/x  X  8/m,  rather 
variable  in  size  and  form. 

S.  Bceomyces  byssoides.  Thallus  granulose,  with  ele- 
vated, flattened  squamules.  Stipes  longer  than  in 
ceruginosus,  flattened  above.  Apothecia  flattened. 
Disk  reddish-brown.  Spores  simple,  colorless,  ellip- 
tical, 10/x  X  -i/A. 

2.  Pilophoron. 

This  genus  is  represented  by  one  well-marked  spe- 
cies, which  is"  of  rare  occurrence.  It  seems  to  be  some- 
what northern  in  its  range,  preferring  moist,  shaded 
places. 

The  primary  thallus  is  deficient,  warty,  greenish- 
gray.  The  vertical  thallus  (secondary  thallus,  or  pode- 
tium)  consists  of  an  erect  stem,  which  may  be  once,  or 
very  rarely  twice,  branched  toward  the  top.  Upon 
examining  a  transverse  section  it  is  found  that  this 
stem  is  hollow  (lumen  is  narrow,  however),  and  that 
it  contains  algjfe  (Protococcus),  thus  being  essentially 
different  from  the  stipe  of  Bceomyces. 

The  apothecia  are  terminal,  globose,  black  or  blue- 
black.  The  spores  are  simple,  oblong  to  spindle- 
shaped,  colorless. 

1.  Pilophoron  cereolus.  Primary  thallus  granular, 
greenish  to  gray  ;  podetia,  from  medium  to  long  and 
slender,  simple,  or  once  or  twice  branched  above,  gran- 
ular, greenish  to  gray.     Apothecia  comparatively  large 


90  GUIDE    TO    THE    STUDY    OF    LICHENS. 

and  numerous,  nearly  spherical.  Thecium  of  a  blue- 
black  tint  near  the  top.  Disk  blue-black,  smooth. 
Spores  simple,  elongated,  colorless,  25.5^  X  7/x. 

3.  Stereocaulon, 

The  most  marked  morphological  character  of  this 
genus  is  the  comparatively  large  fruticose  thallus ;  it 
consists  of  numerous  crooked  and  somewhat  flattened 
branches,  which  are  covered  by  warty  thalloid  out- 
growths. Upon  careful  examination  numerous  dark- 
blue  cephalodia  will  be  found  on  different  parts  of  the 
branches.  The  color  of  the  thallus  is  generally  ash- 
gray. 

The  primary  thallus  is  deficient,  so  much  so  that  the 
average  collector  will  take  no  notice  of  it  whatever. 
The  secondary  thallus  is  not  hollow,  as  in  the  foregoing 
genus  When  dry,  the  Stereocaulons  are  very  brittle. 
They  occur  most  commonly  upon  rocky  ledges  in  hilly 
and  mountainous  regions.  They  are  somewhat  north- 
ern in  their  range. 

The  apothecia  are  terminal,  medium  size,  globose  or 
flattened,  dark-brown  to  nearly  black.  The  spores  are 
colorless,  spindle-shaped,  usually  four-celled.  The  fol- 
lowing are  the  more  common  species : 

1.  Stereocaulon  condensatum.  Primary  thallus  dis- 
tinct, granular  and  warty,  green  to  dark-gray.  Pode- 
tia  short,  branched,  covered  with  thalloid  warts  re- 
sembling those  of  the  primary  thallus.  Apothecia 
rather  large,  simple  or  confluent.  Disk  convex,  dark- 
brown.  Spores  acicular,  triseptate,  colorless,  25/a 
X  2.5/x. 


GENERA    AND    SPECIES.  91 

2.  Stereocaulon  coralloides.  Primary  tliallus  coarsely 
granular  or  warty  in  young  plants,  grayisli-wliite,  usu- 
ally wanting  in  fully  developed  plants.  Podetia  rather 
long  and  slender,  more  or  less  compressed,  much 
branched,  profusely  covered  with  coarsely  granular  or 
warty  outgrowths,  light-gray  to  rather  dark  (cephalo- 
dia  common).  Apothecia  medium,  nearly  spherical, 
often  wanting.  Disk  brown  to  black.  Spores  color- 
less, triseptate,  elongated,  ends  pointed,  27/x  X  6/x. 

3.  Stereocaulon  denudatum.  Primary  thallus  gran- 
ular and  irregularly  globular,  usually  wanting.  Pode- 
tia much  as  in  S.  coralloides^  thalloid  warts  more  or 
less  confluent,  sometimes  flattened,  greenish  to  gray ; 
lower,  hence  older,  portions  of  branches  quite  bare 
(free  from  thalloid  warts),  and  of  a  brownish  color. 
Apothecia  and  spores  as  in  S.  coralloides. 

Jf.  Stereocaulon  ramidosum.  Primary  thallus  of 
flattened  squamules,  with  crenate  margins  usually  want- 
ing. Podetia  usually  long,  otherwise,  as  in  S,  coral- 
loides^ covered  with  flattened  thalloid  warts,  with  cre- 
nate margins.  Apothecia  from  small  to  large,  simple, 
confluent  to  flattened.  Disk,  dark-brown  or  black. 
Spores  as  in  S.  coralloides. 

5.  Stereocaulon  paschode.  Primary  thallus  granular, 
usually  wanting.  Podetia  long,  much  branched,  cov- 
ered with  minutely  branching  outgrowths.  Apothecia 
and  spores  as  in  S.  coralloides. 

Species  2,  3,  4  and  5  are  in  many  respects  closely 
similar ;  so  much  so  that  it  seems  probable  that  they 
are  mere  variations  of  one  species.  Further  oaroful  olv 
servation  and  study  are  necessary  to  prove  whether  or 


92  GUIDE    TO    THE.  STUDY    OF    LICHENS. 

not  this  be  true.  *S'.  paschale  is  a  typical  rock-lichen. 
It  is  said  to  be  the  first  plant  to  develop  upon  the 
volcanic  lava  of  Vesuvius  and  Ischia.  In  various  parts 
of  Europe  wild  animals  feed  upon  it.  In  Lapland  the 
reindeer  often  feed  upon  it  when  Gladonia  rangiferina 
is  scarce. 

Jf..    Cladonia. 

This  genus  is  represented  by  a  great  number  of 
species  which  are  so  variable  and  diversified  in  form 
that  the  systematist  has  considerable  difficulty  in  de- 
fining their  limitations  and  describing  them  clearly. 
It  is,  however,  fortunate  that  nearly  all  of  the  repre- 
sentatives are  readily  recognized  as  belonging  to 
Cladonia.  A  few  species  are  also  quite  characteris- 
tic as  to  form  and  once  seen  are  not  likely  to  be  for- 
gotten or  mistaken  for  any  other  species  ;  such  are  (7. 
rangiferina,  G.  papillaria,  C.  pyxidata,  G.  cariosa, 
and  a  few  others. 

Excepting  in  G.  papillaria,  the  primary  thallus  is 
foliose,  although  the  individual  thalli  are  minute ; 
sometimes  simple  and  entire,  again  considerably  lobed 
or  even  distinctly  branching.  Usually  a  large  num- 
ber of  thalli  occur  together,  more  or  less  imbricate 
with  one  side  elevated.  The  upper  surface  is  dis- 
tinctly bright-green,  the  iower  surface  whitish.  The 
vertical  thallus  (secondary  thallus,  podetium)  is 
very  variable  in  form  ;  from  simple  to  much 
branched.  The  simple  forms,  again,  vary  as  to  size 
and  structure ;  some  are  nearly  smooth,  while  others 
bear  numerous  leafy  outgrowths  resembling  the  pri- 
mary  thalli ;    some   are    cup-like    toward    the    apex. 


GENERA    AND    SPECIES.  93 

while  others  have  several  of  these  cup-like  or  dis- 
coid expansions  at  regular  intervals.  The  branching 
forms  also  vary  greatly  as  to  size,  manner  of  branch- 
ing, etc.  The  color  varies  somewhat ;  greenish-gray, 
however,  prevails.  The  podetia  are  hollow,  and  ex- 
emplify a  mechanical  type  especially  adapted  to  re- 
sist lateral  forces  (air  currents). 

The  apothecia  are  terminal  upon  the  podetial 
branches,  or  short  apothecial  stalks  borne  upon  the 
margin  of  the  cup-shaped  or  cfiscoid  expansions. 
They  are  usually  simple  or  more  or  less  confluent, 
globose,  either  brown  or  bright-scarlet.  The  scarlet 
apothecia  at  once  prove  the  specimen  a  species  of 
Cladonia.  The  spores  are  simple,  elliptical,  color- 
less, and  vary  little  in  the  different  species.  It  must 
also  be  remembered  that  some  of  the  higher  Cladonias 
are  constantly  sterile. 

The  Cladonias  are  widely  distributed  ;  they  occur 
upon  soil  and  rock,  less  commonly  upon  tree-trunks 
and  fences.     They  are  northern  in  their  range. 

1.  Cladonia  papillaria.  Primary  thallus  crustose 
to  warty.  Podetia  (secondary  thalli)  short,  smooth, 
club-shaped,  somewhat  tapering  near  the  apex. 
Apothecia  rare  in  some  localities,  small,  more  or  less 
confluent.  Disk  convex,  brown.  Spores  simple,  ellipti- 
cal, colorless.* 

^  This  species  is  quite  common  on  soil  in  the  hilly 
districts    of    New   Jersey  and    eastern   Pennsylvania. 

»  The  spores  of  the  Cladonias  are  so  closely  siiuilHr  that  the 
measurements  ami  special  descriptions  will  be  oniiited  in  most 
instances.  The  average  measurements  are  14  microns  in  length  by  4 
miorons  in  width.  ' 


94'  GUIDE    TO    THE    STUDY    OF    LICHENS. 

Formerly  it  was  classified  with  another  genus  {Pyc- 
nofhelia),  which  is  not  at  all  surprising  because  it  cer- 
tainly has  few  characters  in  common  with  most  (7/a- 
donias. 

2.  Gladonia  delicata.  Primary  thallus  consists  of 
numerous  medium  sized,  closely  crowded  lobes, 
which  are  sometimes  finely  branched.  Podetia  short, 
slender,  sometimes  branching  above.  Apothecia 
medium,  confluent.  Disk  convex,  brown.  Spores 
rather  small. 

3.  Gladonia  ccespiticia.  Primary  thallus  well 
developed,  much  cleft  or  irregularly  branching. 
Podetia  very  short  or  wanting.  Apothecia  medium. 
Disk  convex,  brown.  Spores  comparatively  numer- 
ous and  a  little  above  the  average  in  size. 

J/.,  Gladonia  symphycarpa.  Primary  thalli  well 
developed,  usually  rounded,  sometimes  elongated, 
branching  inconspicuous,  upper  surface  generally 
convex.  Podetia  short,  rather  thick,  slightly 
branching.  Apothecia  well  developed.  Disk  con- 
vex, confluent,  dark-brown.  Spores  rather  large, 
15/x  X  3.5/A. 

5,  Gladonia  mitrula.  Primary  thalli  usually 
small,  numerous,  rounded,  almost  entire,  sometimes 
much  enlarged  and  branching.  Podetia  from  short 
to  medium,  entire  or  rarely  branching  near  the 
apex.  Apothecia  medium  to  large,  usually  conflu- 
ent.    Disk  convex,  brown.     Spores  numerous. 

6.  Gladonia  pulchella.  Primary  thallus  well  de- 
veloped ;  lobes  branched,  elongated,  slender.  Podetia 
somewhat  elongated,  branched  toward  the  apex,  bear- 


GENERA    AND    8PKCIE8.  95 

ing  thalloid  outgrowths.  Apothecia  rather  large,  usu- 
ally coufluent.  Disk  convex,  scarlet.  Spores  normal 
in  size  and  form. 

7.  Gladonia  cariosa.  Primary  thallus  usually  well 
developed ;  lobes  from  small  and  simple  to  large  and 
irregularly  branching,  with  crenate  margin.  Podetia 
of  medium  length,  expanded  and  irregularly  branch- 
ing above,  warty.  Apothecia  numerous,  rather  large. 
Disk  convex,  brown.  Spores  colorless,  elliptical,  sim- 
ple, Utx  X  3.5/x. 

8.  Gladonia  decorticata.  Primary-  thallus  fairly 
well  developed  ;  lobes  usually  small  and  almost  entire, 
sometimes  large  and  much  branched,  margin  crenate. 
Podetia  medium  to  long,  branched  above,  finely  gran- 
ular and  sometimes  bearing  thalloid  outgrowths,  but 
soon  becoming  decorticate,  beginning  at  the  base.  Apo- 
thecia very  numerous,  medium  size,  confluent.  Disk 
convex,  brown.     Spores  rare. 

9.  Gladonia  macilenta.  Lobes  of  primary  thallus 
scattered  over  substratum,  variable  in  size  and  branch- 
ing ;  margins  distinctly  crenate.  Podetia  medium,  slen- 
der to  rather  thick,  covered  by  scaly  thalli  which  dis- 

*appear  after  a  time.  Apothecia  medium  to  large,  con- 
fluent.    Disk  convex,  scarlet.     Spores  normal. 

10.  Gladonia  cristatella.  Primary  thallus  fairly  well 
developed;  lobes  from  small  and  almost  entire  to  large 
and  branching,  usually  more  or  less  adnate.  Podetia 
medium,  branched  above,  rarely  simple,  gniiiular,  bear- 
ing secondary  thalli.  Apothecia  very  numerous,  me- 
dium size,  confluent.  Disk  convex,  scarlet.  Spores 
rare. 


96  GUIDE    TO    THE    STUDY    OF    LICHENS. 

11.  Gladonia  cenotea.  Primary  thallus  usually 
absent ;  when  present,  large,  elongated  and  much 
branched.  Podetia  rather  long  and  thick,  branched 
near  the  top,  lower  portion  often  bearing  thalloid  lob- 
ules. Apothecia  rare.  Disk  flesh-colored  to  dark- 
brown.     Spores  usually  wanting. 

12.  Gladonia  alcicornis.  Primary  thallus  well  de- 
veloped, much  elongated,  branched,  margin  crenate. 
Podetia  not  very  numerous,  often  wanting,  medium 
height  and  thickness,  much  expanded  above,  either  cup- 
shaped  or  leaf-like,  bearing  a  few  usually  large  thalloid 
lobules.  Apothecia  sessile  or  on  short  stalks,  rather 
small.     Disk  convex,  light-brown  to  reddish-brown. 

13.  Gladonia  lepidota.  Primary  thallus  of  much 
elongated  and  divided  lobes.  Podetia  medium,  spar- 
ingly branched  toward  the  base  ;  much  branched  near 
the  apex,  bearing  many  thalloid  lobules.  Apothecia 
often  wanting. 

1^.  Gladonia  pyxidata.  Primary  thallus  well  de- 
veloped; lobes  rather  large,  broad,  and  indistinctly 
branched.  Podetia  from  short  to  medium  in  length, 
from  medium  to  very  thick,  much  expanded  above,  not 
branching,  scaly,  sometimes  bearing  a  few  thalloid 
lobules.  Apothecia  rare,  on  short  stalks,  small.  Disk 
convex,  somewhat  confluent,  brown. 

Lindsay  says  of  this  lichen,  "  It  is  the  '  cup-moss  '  of 
the  London  herbalists.  It  contains  a  considerable 
quantity  of  gummy  or  starchy  matter,  and  has  been 
much  used  as  a  demulcent  in  various  chest  affections." 
Its  medicinal  uses,  which  have  been  most  varied,  have 
resembled  those  of  Getraria  Islandica, 


GENERA   AND    SPECIES.  97 

15.  Cladonia  deformis.  Primary  thallus  sparingly 
present  or  wanting.  Podetia  from  medium  to  long, 
very  rarely  bearing  thalloid  lobules,  rather  thick,  ter- 
minating in  a  cup  which  becomes  degenerate  and  indis- 
tinct with  age.  Apothecia  on  secondary  branches  of 
considerable  length,  which  grow  from  the  margin  of 
the  cup  ;  rather  large,  confluent.     Disk  convex,  scarlet. 

16.  Cladonia  hellidi flora.  Primary  thallus  fairly 
well  developed.  Lobes  rather  large,  irregularly  branch- 
ing. Podetia  long,  thick  to  very  thick,  rarely  branch- 
ing, usually  covered  with  thalloid  lobules.  Apothe- 
cia large,  irregular  in  outline.  Disk  a  bright-scarlet. 
Spores  13.5/i,  X  3.5yot. 

n.  Cladonia  cornucopioides.  Primary  thallus- 
lobes  irregularly  scattering,  rather  long,  branching. 
Podetia  of  medium  length,  rather  thick,  expanded, 
trumpet-shaped  above,  covered  by  minute  scaly  warts. 
Apothecia  on  short  stalks  growing  from  the  edge  of 
the  expanded  portion  ;  entire,  orbicular  to  elongated, 
variable  in  size  and  form.  Disk  bright-scarlet. 
Spores  10/a  X  2.5/x. 

"  This  is  probably  the  '  red  cup-moss  '  of  which  Mrs. 
Hemans  sings  in  the  following  stanza : 

" '  Oh !  green  is  the  turf  where  my  brothers  play 
Through  the  long  bright  hours  of  the  summer  day  ; 
They  find  the  red  cup-moss  where  they  climb. 
And  they  chase  the  bee  o'er  the  scented  thyme.' 

"  It  occurs  in  the  antarctic  regions  and  is  otherwise 
somewhat  widely  distributed.  It  appears  to  contain  a 
small  quantity  of  gummy  and  starchy  matter  ;  hence 


98  GUIDE    TO    THE    STUDY    OF    LICHENS. 

it  lias  been  used,  boiled  in  milk  or  syrup,  in  whooping- 
coush  and  other  chest  affections  in  children.  In  Thu- 
ringia,  a  decoction  has  been  used  in  the  treatment  of 
intermittent  fevers."  —  Lindsay, 

18.  Cladonia  digitata.  Primary  thallus  large,  rarely 
branching,  minutely  lobed  with  crenate  margin.  Pode- 
tia  medium  in  length,  from  slender  to  thick,  expanded 
into  an  irregular  cup  with  incurved  margin  ;  secondary 
branches  show  a  palmate,  one-sided  development  from 
the  margin  of  the  cup,  that  is,  some  of  the  secondary 
branches  remain  rudimentary.  Apothecia  usually  borne 
on,  secondary  branches,  rarely  on  short  stalks  ;  conflu- 
ent.    Disk  convex  or  slightly  concave,  scarlet. 

19.  Cladonia  gracilis.  Primary  thallus  of  rather 
large  scattering  lobes,  branching  usually  once  or  twice. 
Podetia  long,  slender,  variable,  sometimes  simple  and 
pointed,  again  more  or  less  branching,  sometimes  bear- 
ing rather  small  cups  from  which  one  or  more  branches 
of  considerable  size  develop.  Apothecia  medium,  on 
short  stalks.     Disk  convex,  brown. 

20.  Cladonia  fimhriata.  Primary  thallus  rather 
large,  more  or  less  scattered,  usually  once  or  twice  di- 
vided, margin  crenate.  Podetia  usually  long,  slender, 
sparsely  branched,  sometimes  terminating  in  a  cup, 
attenuately  pointed,  rarely  bearing  thalfoid  lobules, 
white,  smooth  or  granular,  becoming  decorticate.  Apo- 
thecia terminal  on  small  branches  from  the  margin  of 
the  cups,  medium,  confluent.     Disk  convex,  brown. 

21.  Cladonia  verticillata.  Primary  thalli  sparingly 
present.  Lobes  from  small  to  medium,  more  or  less 
orbicular,  scattering.     Podetia  from  medium  to  very 


GENERA    AND    SPECIES.  99 

long,  rather  slender,  expanded,  cup-like,  bearing  here 
and  there  a  few  thalloid  lobules,  branches  sometimes 
formed  on  the  cups  or  the  margins  of  the  cups.  Apo- 
thecia  usually  rare,  on  short  stalks  from  the  margins 
of  the  cups,  small  to  medmm.     Disk  convex,  brown. 

22.  Cladonia  squamosa.  Primary  thallus  well  de- 
veloped, slender,  elongated,  variable  in  size  and 
frequency  of  branching.  Podetia  rather  long  and 
slender,  irregularly  branched,  branches  decreasing  in 
length  and  thickness  directly  with  the  number  of  di- 
visions, bearing  many  thalloid  lobules.  Apothecia 
rather  small.  Disk  convex,  brown.  Spores  compara- 
tively numerous,  12/x  X  3.5^. 

23.  Cladonia  turgida.  Pr  mary  thallus  large, 
elongated,  branched.  Podetia  long,  rather  thick, 
irregularly  branched,  sometimes  perforate.  Apothecia 
rare,  small,  hemispherical,  on  short  slender  branches. 
Disk  light  reddish-brown.     Spores  very  rare. 

24.'  Cladonia  uncialis.  Primary  thallus  deficient 
or  wanting.  Podetia  in  dense  clusters,  much  ex- 
panded, branching,  more  or  less  perforate,  terminal 
branches  pointed,  usually  sterile.  "  Podetia  incras- 
sated  above,  cymose,  brown." 

25.  Cladonia  furcata.  Primary  thallus  consisting 
of  a  few  small  scattering  lobes,  sometimes  becoming 
large,  and  indistinctly  branched.  Podetia  long,  rather 
slender,  frequently  branched  (thickness  and  length  of 
branches  decreasing  with  the  number  of  divisions), 
smooth,  whitish,  bearing  thalloid  lobules.  Apothecia 
from  small  to  medium.  Disk  convex,  brown.  Spores 
rather  large  (long). 


100  GUIDE    TO    THE    STUDY    OF    LICHENS. 

26.  Cladonia  leporina.  Primary  thallus  rare. 
Lobes  narrow  and  much  branched,  quite  rigid. 
Podetia  rather  long,  distinctly  and  uniformly  twice 
branched,  quite  smooth.  Apothecia  small.  Disk 
convex,  scarlet. 

27.  Cladonia  amaurocroea.  Primary  thallus  de- 
ficient or  wanting.  Podetia  long,  slender,  much 
branched,  terminal  branches  not  bearing  sperma- 
gonia  are  pointed.  Apothecia  rather  small.  Disk 
flat  or  slightly  concave,  margin  and  a  central  portion 
often  somewhat  elevated,  reddish-brown.  Spores 
lOya  X  4.5/x. 

28.  Cladonia  rangiferina.  Primary  thallus  often 
wanting.  Podetia  long  and  rather  slender,  frequently 
branching,  smooth,  greenish  to  ash-gray,  terminal 
branches  short,  somewhat  recurved.  Apothecia  are 
frequently  wanting,  small,  simple.  Disk  convex, 
brown. 

"  Crabbe  calls  it  truly, 

"'The  wiry  moss  that  whitens  all  the  hill/ 

" '  Omnium  lichenum  copiosissima,'  according  to 
Fries,  —  it  is  almost  a  cosmopolite,  but  its  geo- 
graphical range  is,  in  various  parts  of  the  world,  very 
irregular  and  limited.  In  Northern  Europe  it  is  used, 
like  Certaria  Islandica,  as  a  nutrient  and  demulcent. 
It  is  a  social  plant,  covering  in  Lapland  vast  tracts  of 
country,  and  growing  to  a  height  of  six  to  twelve 
inches.  The  barren  plains  so  covered  are  the  favor- 
ite and  only  pasture  of  the  reindeer  during  winter; 
the  animals  clear  away  the  snow  by  means  of  their 


GENERA    AND    SfEClES.  101 

horns  to  browse  on  the  lichen.     It  is  also  frequently 
collected,  like  hay,  as  fodder  for  cattle  during  winter 
and  for  the  reindeer  on  journeys.     Parry,  in  the  nar- 
rative of  his  fourth  voyage,  mentions  his  officers  col- 
lecting supplies  of   this  lichen  as    provender  for  the 
reindeer,  which  he  used  in  the  capacity  of  horses  ;  he 
adds,  '  It  required  a  great  deal  of  picking  *  to  separ- 
ate it  from  the  moss,  among  which  it  usually  grows. 
The  daily  quantity  of  cleaned  'reindeer  moss'  —  as 
it  is  popularly  denominated  —  necessary  for  each  ani- 
mal on  a  journey  is  four  pounds ;  but,  he  remarks,  it 
can  easily  remain  for  five  or  six  days  without  food. 
To  prepare  it  as  fodder  for  cattle,  in  some  northern 
countries,  hot   water  is    poured   over   it ;  it   is    then 
mixed  with  straw,  and  a  little  salt  sprinkled  over  the 
mixture.     Cattle  so  fed  are  said  to  produce  delicious 
milk   and  butter,  while    their  flesh  becomes  fat  and 
sweet.    Bucke,  in  his  '  Harmonies  of  Nature,'  speaks 
of  small  cows,  by  feeding  on  this  lichen,  whose  milk 
becomes  wholly  cream.     The  stag,  deer,  roebuck  and 
other  wild  animals  also  feed  on  it  abundantly  during 
winter.     But  it  is  not  only  serviceable  as  food  to  the 
lower  animals,  —  man  himself  is  frequently  compelled 
to  use  it  in  times  of  scarcity.     It  is  sometimes  pow- 
dered, mixed  with  flour  and  baked  into  bread  ;  or  it 
is  boiled  in  milk  or  broth.     Clarke,  in  his  '  Travels,' 
mentions  having  eaten  it,  and  even   speaks   of  it  in  a 
commendatory  way.     It  is  sold  by  the  London  herbal- 
ists for  the  purposes  of  the  bird-stuffer.     In  a  pulver- 
ized state  it  at  one  time  formed  a  frecjueut  ingredient 
in  hair-powders  and  perfumes."  —  Lindsay. 


102  GUIDE    TO    THE    STUDY    OP    LICUeNS. 

5.   Thamnolia. 

This  genus  is  represented  by  one  species  only.  It 
is  quite  probable  that  it  belongs  to  Oladonia  ;  in  fact, 
that  is  the  position  given  it  by  many  lichenologists. 

The  primary  thallus  is  wanting.  The  podetia  are 
quite  free  from  warts  or  excrescences,  hollow,  simple 
or  sparingly  branched.  They  are  widest  at  the  bot- 
tom, gradually  tapering  upward,  a  character  not  oc- 
curring in  the  simpler  podetia  of  Cladonia.  Color 
varies  from  greenish-gray  to  pale  straw-color. 

No  apothecia  have  been  found  ;  it  is  propagated  by 
means  of  soredia,  and  also  vegetatively. 

It  occurs  upon  rock  and  soil  in  the  higher  altitudes 
and  latitudes. 

1.  Thamnolia  vermicularis.  Primary  thallus  want- 
ing. Podetia  rather  long,  usually  simple,  sometimes 
one  or  more  short  branches  toward  the  apex,  thin, 
tapering,  sometimes  wrinkled  longitudinally,  color  as 
above.     No  apothecia,  and  hence  no  spores. 

III.    LECIDEACE^. 

Stipes  and  podetia  are  wholly  wanting  in  this 
family,  which  distinguishes  it  from  the  preceding 
families.  The  apothecia  are  sessile  upon  the  thallus, 
discoid,  and  belong  to  the  fungal  type.  The  disk  is 
generally  convex  or  flattened.  The  thallus  varies 
from  crustose  to  distinctly  foliose,  never  fruticose. 
The  foliose  thalli  are  entire,  not  distinctly  lobed  or 
branched. 

It  must  be  stated  that  considerable  doubt  exists  as 
to  the  exact  limitations  of  this  family.     Some  of  the 


GENERA    AND    SPECIES.  103 

t 

lower  genera  here  included  present  widely  different 
spore-chanicters,  which  would  perhaps  indicate  a  re- 
moter relationship  than  is  assumed.  In  some  instances 
the  thallus  is  very  rudimentary.  Because  of  the  ab- 
sence of  well-marked  family-characters,  the  amateur 
is  likely  to  confuse  some  of  the  lower  genera  with  the 
lower  genera  of  the  ParmeliacecB,  and  perhaps  some 
Verrucariacece,  to  be  considered  later. 

KEY  TO  THE   GENERA. 
Thallus  indistinctly  crustose  to  Avarty. 
Spore-sacs  bearing  sixteen  simple  colorless  spores, 

o                   ,        .         .   ,  1-  Biatorella. 
Spore-sacs  bearing  eight  spores  (usual  number). 
Hypothecium  and  spores  colorless. 
Spores  elliptical. 

Two-celled ^.  Biatorina. 

^^'"P^e         s.  Biatora. 

Four-celled ^.  BiUmbia. 

bpores  acicular,  six  to  eight-celled  .  .5.  Bacidia. 
Hypothecium  dark. 
Spores  colorless. 

Simple 6.  Lecidea. 

Two-celled 7.   CatiUaria. 

Four-eel  ed g.  Cdidiopsis. 

Spores  dark. 

Two-celled 5.  BnelUa. 

Four-celled     , jO.  Buellopsis. 

bpore-sacs  bearing  from  one  to  six  spores,  hypothecium 
colorless  or  yellowish. 

Spores  simple,  colorless,  large     .     .  11.  Megahspora. 
Spores  multilocular.i 

^^^^: 1^.  Lopadium. 

rry.  11      F?-'"''''''' ^3-   Gyalecta. 

Thallus  fohose,  entire. 

Small,  adnate  to  substratum,  spores  simple,  colorless, 
T  ,  .,.  ^4-  Psora. 

-Large,  umbilicate ;  apothecia  black,  sessile. 

Spores  simple,  colorless 15.  Gf/rophora. 

Spores  multilocular,  large  ....      16.   Umbilicaria. 

-^.^^/''""l'-'*'*'"'^'".''^"*'^^"  '»  nieant  many  celled  spores  havine 
■epta  formed  m  two  plants  of  thespore.  i^v.icb   imviug 


104  GUIDE    TO    THE    STUDY    OF    LICHENS. 

1.  Biatorella. 

A  very  insignificant  group  ;  only  one  species  has 
come  to  my  notice.  The  thallus  is  very  rudimentary 
or  entirely  wanting  ;  repeated  search  is  necessary  to 
detect  the  algae  (Protococcus).  The  apothecia  are 
small,  dark  and  considerably  scattered,  which  adds  to 
the  difficulty  of  finding  specimens.  The  spores  are 
simple,  small  and  colorless,  sixteen  usually  occurring 
in  each  spore-sac. 

The  Biatorellas  seem  to  prefer  sterile  soil. 

1.  Biatorella  geophana.  Thallus  deficient  or  want- 
ing. Apothecia  small.  Disk  convex,  dark-brown. 
Spores  simple,  nearly  spherical,  colorless,  8/a  X  7/x. 

2.  Biatorina. 

This  genus  is  likewise  deficient  in  representatives. 
The  thallus  is  rudimentary  but  readily  recognizable ; 
it  is  usually  greenish  in  color  and  uniformly  crustose, 
never  becoming  warty  or  areolate.  The  algae  are 
bright-green,  occurring  in  chains  of  rather  small  cells 
(^Chroolepus  umhrina).  The  apothecia  are  quite 
small.  Disk  flattened  or  slightly  concave,  brown  or 
even  pale-brown.  Some  authors  combine  this  group 
with  Biatora ;  but  the  elliptical,  colorless,  two-celled 
spores  exclude  it.  They  occur  upon  soil,  tree-trunks 
and  moss. 

1.  Biatorina  lutea.  Thallus  thin,  evenly  spread- 
ing, somewhat  granular,  light-gray  to  greenish. 
Apothecia  rather  small,  discoid.  Disk  of  a  yellow- 
ish waxy  color.  Spores  colorless,  elliptical,  two-celled, 
15/*  X  5/x. 


GENERA    AND    SPECIES.  105 

^.  Biatorina  pineti.  Th alius  very  rudimentary, 
dark.  Apothecia  very  small.  Disk  dark.  Spores 
as  in  B.  lutea. 

B.  lutea  occurs  upon  moss,  while  B.  pineti  occurs 
upon  pine  trees.     Both  are  quite  rare. 

3.  Biatora. 

This  genus  is  represented  by  a  considerable  num- 
ber of  species.  Some  authors  have  made  it  the 
dumping  ground  for  many  lichens  which  have  no 
evident  affinity  to  the  typical  representatives.  Thus, 
for  example,  Biatorella,  Biatorina,  Bilimhia,  Bacidia, 
Psora,  Acarospora,  etc.,  have  been  included  in  Bia- 
tora, and  are  yet  so  included  by  some  recent  authors. 
This  is  no  doubt  primarily  due  to  insufficient  attention 
to  spore-differences. 

The  thallus  varies  from  typically  crustose  to  warty 
and  minutely  foliose.  The  color  tends  toward  gray- 
ish-green. The  algae  are  Protococcus  (^Cystococ- 
cus). 

The  apothecia  are  of  medium  size,  discoid.  Disk 
flattened  to  convex,  light-brown  to  dark  and  black. 
The  hypothecium  is  colorless.  Spores  are  elliptical, 
simple,  colorless. 

The  Biatoras  are  widely  distributed,  and  occur  upon 
bark,  less  commonly  upon  rock  and  moss.  They  are 
active  in  the  disintegration  of  rock,  but  much  less  so 
than  their  near  relatives,  the  Lecideas. 

The  following  are  the  more  common  species. 

1.  Biatora  varians.  Thallus  thin,  granular,  gray- 
ish-green ;    margin    dark.      Apothecia    small,  sessile, 


106  GUIDE    TO    THE    STUDY    OF    LICHENS. 

irregular  margin.     Disk  yellowish  to  brown.     Spores 
ovoid  or  nearly  spherical,  colorless,  7fx  to  1  Ofx. 

This  species  has  many  characters  peculiar  to  the 
lower  Lecanoras,  which  would  make  it  seem  proper  to 
place  it  with  that  group. 

2.  Biatora  myriocarpoides.  Thallus  thinly  crus- 
tose  and  of  a  dark  muddy  color.  Apothecia  small, 
sessile.  Disk  flat  or  slightly  convex,  dark.  Spores 
elliptical,  colorless,  8.5//,  to  9/x. 

The  hypothecium  is  generally  dark  or  even  black, 
which  would  point  toward  the  Lecideas ;  but  the 
color  variations  of  the  hypothecium  are,  however, 
too  great  to  be  reliable  as  a  generic  character. 

3.  Biatora  uliginosa.  Thallus  consists  of  minute 
granular  elevations,  color  varies  from  gray  to  dark  or 
black.  Apothecia  small,  few  in  number.  Disk  flat- 
tened, sometimes  convex,  dark  color.  Spores  ellipti- 
cal, colorless,  rarely  two-celled,  22/a  X  8/x. 

Jf.  Biatora  contigua.  Thallus  evenly  spreading, 
scaly  or  squamose,  light-gray.  Apothecia  compara- 
tively large,  numerous,  sessile.  Disk  convex,  some- 
times flattened,  black  with  a  translucent  white  film 
which  is  characteristic  of  the  species.  Spores  ellip- 
tical, colorless,  22^  X  ^/x. 

5.  Biatora  diapensice.  Thallus  rudimentary,  color 
whitish.  Apothecia  of  medium  size.  Disk  generally 
convex,  reddish-brown  or  black.  Spores  colorless, 
elliptical,  10/i,  X  3.5yu,. 

The  hypothecium  is  occasionally  blac^:,  and  this 
plant  may,  therefore,  be  mistaken  for  a  species  of 
Lecidea. 


GENERA    AND    SPECIES.  107 

<J.  Biatora  vernalis.  Thallus  thin,  granular,  gray 
to  greenish.  Apothecia  variable  in  size,  sometimes 
in  clusters.  Disk  yellowish  to  tawny,  sometimes 
black.  Spores  elliptical  to  oblong,  often  indistinctly 
two-celled,  colorless,  15/a  X  7/x,. 

7.  Biatora  russiila.  Thallus  granular,  ash-gray  to 
greenish.  Apothecia  small  to  medium.  Disk  flat  or 
convex,  brick-red.  Spores  colorless,  oblong,  some- 
times indistinctly  two-celled,  11/t  X  8.5/x. 

8.  Biatora  petiaspis.  Thallus  indistinct,  dark-brown 
to  black.  Apothecia  medium  size.  Disk  varying  from 
grayish  to  black.  Spores  variable  in  size  and  form, 
simple,  colorless,  averaging  10/x  X  4.5/x,. 

The  hypothecium  is  often  brown  to  dark  in  color, 
perhaps  never  entirely  black. 

9.  Biatora  parvifolia.  Thallus  usually  distinct, 
minutely  thalloid  or  scaly,  pale-green  to  yellowish- 
green  or  even  reddish-brown.  Spores  oblong,  color- 
less, simple,  14/x  by  4/x. 

As  the  name  (^parvifolia)  indicates,  this  is  in  reality 
a  foliose  lichen,  but  the  lobes  are  so  insignificant 
that  the  average  collector  will  take  it  for  a  crustose 
lichen. 

10.  Biatora  granulosa.  Thallus  distinct,  of  gray- 
ish-white, smooth  wart-like  elevations  which  often  bear 
greenish  soralia.*  Apothecia  of  medium  size.  Disk 
convex,  usually  black,  sometimes  dark-brown  or  red- 
dish. Spores  variable  in  size  and  form,  simple,  color- 
less or  faintly  yellowish-brown,  IG/x  X  7/x,. 

11.  Biatora  cinnaharina.     Thallus   granular,   con- 

»  Soralia  are  aggregates  of  soredi;i  which  may  occur  as  circular  or 
linear  patches.    The  word  was  iutroduced  by  Reinke  (1895). 


108  GUIDE   TO    THE    STUDY    OF   LICHENS. 

sisting  of  numerous  raiuute  but  distinct  elevated  gran- 
ules, whitish  to  yellowish-green.  Apothecia  medium 
size.  Disk  convex,  bright-scarlet.  Spores  oblong, 
often  somewhat  larger  at  one  end,  simple,  colorless. 
24/x  X  4/x. 

This  species  does  not  occur  in  the  northeastern 
United  States.  It  is  western  and  southern  in  its 
range. 

Jf.  Bilimhia. 

This  is  another  insignificant  group  represented  by 
only  a  few  species.  Its  general  characters  correspond  to 
those  of  the  Biatoras  and  Lecideas.  Various  authors 
include  it  under  Biatora. 

The  thallus  is  crustose,  never  becoming  foliose  as  in 
some  of  the  Biatoras.  The  apothecia  are  of  medium 
size.  Disk  flattened  or  convex,  color  yellowish-brown 
to  dark-brown.  The  algse  are  in  all  probability  Proto- 
coccus,  but  differ  from  the  usual  forms  in  their  small 
size.  Spores  are  spindle-shaped,  colorless,  usually 
four-celled. 

The  Bilimhias  occur  upon  tree-trunks  and  moss. 

1.  Bilimhia  mixta.  Thallus  granular,  warty,  whitish, 
or  faintly  yellow.  Apothecia  small,  adnate.  Disk 
convex,  usually  black.  Spores  oblong,  two  to  four- 
celled,  colorless,  sometimes  slightly  curved,  18/i,  X  5/x. 

2.  Bilimhia  hypnophila.  Thallus  granular,  spread- 
ing, greenish  to  gray.  Apothecia  small,  sessile,  un- 
evenly convex.  Disk  black,  thecium  and  hypothecium 
reddish-brown.    Spores  as  in  B.  mixta. 

3.  Bilimhia  sphceroides.  Thallus  distinct,  uniformly 
spreading,  granular,  greenish,     Apothecia  nearly  glo- 


GENERA    AND    SPECIES.  109 

bose,  attached  by  a  narrow  neck.     Disk  yellowish  or 
tawny.     Spores  as  in  B.  mixta. 

5.  Bacidia, 

This  genus  is  represented  by  a  considerable  num- 
ber of  species  and  is  well  characterized,  although  some 
authors  include  it  under  Biatora,  no  doubt  because  in 
its  gross  characters  it  resembles  that  genus. 

The  thallus  is  typically  crustose,  sometimes  becom- 
ing indistinctly  areolate  or  coarsely  granular,  color 
gray  to  greenish.  The  alga?  are  Proto§occus.  The 
apothecia  are  of  medium  size.  Disk  convex  to  flat- 
tened, light-brown  to  black  ;  the  hypothecium  varies 
from  dark-brown  to  nearly  black.  Tlie  spores  are 
much  elongated,  acicular,  more  narrow  toward  one 
end,  colorless,  five  to  eleven-celled,  variable  in  size  and 
form. 

This  genus  is  southern  in  its  range.  They  generally 
occur  upon  tree-trunks,  more  rarely  upon  rock  and 
moss. 

1.  Bacidia  albescens.  Thallus  thinly  granular,  green- 
ish to  gray.  Apothecia  small.  Disk  convex,  pale-yel- 
lowish or  pale-brown.  Spores  very  slender,  indistinctly 
septate,  35/t  X  1.8//,. 

2.  Bacidia  cuprea-rosella.  Thallus  granular  to  squa- 
mose,  light-gray  to  greenish-gray.  Apothecia  small. 
Disk  convex,  yellowish  to  reddish-brown.  Spores 
comparatively  short  and  thick,  usually  blunt  at  both 
ends,  five-celled,  colorless,  17/x  X  3/4,. 

3.  Bacidia  chlorosticta.  Thallus  deficient,  minutely 
granular,  gray  to   greenish.      Apothecia  very   small. 


110  GUIDE    TO    THE    STUDY    OF    LICHENS. 

Disk  convex,  black.  Spores  small,  slender,  more  or 
less  curved,  five  to  seven-celled,  colorless,  20/a  X  1-5/x. 
J,.,  Bacidia  atrogrisea.  Thallus  granular,  greenish 
to  gray.  Apothecia  rather  small.  Disk  convex, 
black.  Spores  nine  to  eleven-celled,  pointed  at  both 
ends,  variable  in  length  and  width,  colorless,  60/x 
X  5/x. 

5.  Bacidia  inundata.  Thallus  granular,  or  more 
or  less  squamosa,  greenish  to  gray.  Apothecia  small. 
Disk  convex,  brown  to  black.  Spores  seven  to  nine- 
celled,  indistiiactly  septate,  colorless,  31/a  X  2/x. 

6.  Bacidia  rubella.  Thallus  of  distinct,  more  or 
less  scattered  granules,  greenish  to  gray.  Apothecia 
of  medium  size.  Disk  reddish-brown  to  dark-brown. 
Spores  colorless,  nine  to  eleven-septate,  50/x  X  4/x. 

7.  Bacidia  suffusca.  Thallus  thinly  granular,  green- 
ish to  ash-gray.  Apothecia  of  medium  size  to  quite 
large,  raised  margin.  Disk  reddish-brown  coated  with 
a  translucent  whitish  film,  giving  it  a  characteristic 
appearance.  Spores  seven  to  nine-celled,  colorless, 
50/x  X  V 

8.  Bacidia  Schweinitzii.  Thallus  granular,  form- 
ing a  thin  crust,  greenish  to  ash-gray.  Apothe- 
cia of  medium  size.  Disk  brown  to  black.  Spores 
colorless,  seven  to  nine-celled,  55/x  X  4/x. 

6.  Lecidea. 

The  representatives  of  this  genus  resemble  the 
Biatoras  very  closely,  so  much  so  in  fact  that  it 
would  seem  advisable  to  combine  the  genera.  The 
only  essential  difference  seems  to  be  the  greater  pre- 


28 


J 


I'LATi:  I^.  ( 'rust,, SI-  Typfs.  Kimi,  il.,-  r..ll,-,-t  ion  ut  X. 
V.  ('l;irk  111  tli«'  lifibaliiiiii  «•!  iln-  (  aliloinia  A.a.i»-iii>  <'i 
Science.      Ltrhlta  inh-i-nlfurti. 


GENERA    AND    SPECIE^.  Ill 

dominance  of  dark  coloration  in  the  Lecideas,  espe- 
cially in  the  disk  and  hypothecium.  The  Lecideas  are 
also  more  brittle.  As  in  Biatora,  the  spores  are  sim- 
ple, elliptical  and  colorless. 

The  majority  of  the  species  occur  upon  rock,  some 
upon  trees  and  fences.  They  play  a  very  important 
part  in  the  disintegration  of  rock. 

The  Lecideas  have  the  widest  range  of  distribution: 
they  occur  at  all  latitudes  and  altitudes.  Lecidca 
geographica  occurs  far  above  the  line  of  perpetual 
snow  ;  it  forms  the  last  vegetation  of  the  Andes,  the 
Himalayas  and  the  arid  peaks  of  Nova  Zembla. 

1.  Lecidea  panceola.  Thallus  consists  of  rather 
thick,  closely  crowded  squamules,  which  are  convex 
above  and  of  irregular  outline  ;  ash-gray  to  dirty 
brown.  Apothecia  comparatively  large  ;  sometimes 
two  or  three  are  united.  Disk  convex,  dark-brown  to 
black.     Spores  simple,  colorless,  elliptical,  14/a  X  4.5/x. 

2.  Lecidea  enteroleuca.  Thallus  granulose  to  in- 
distinctly squamose,  ash-gray  to  greenish.  Apothecia 
small  to  medium.  Disk  flattened,  margin  somewhat 
raised,  black.  Spores  simple,  colorless,  elliptical, 
Ufx  X  6/.. 

3.  Lecidea  melancheima.  Thallus  coarsely  granu- 
lar, rugose  or  warty,  gray  or  greenish-white.  Apothe- 
cia of  medium  size.  Disk  convex,  black.  Hypothe- 
cium yellowish  or  faintly  brown.  Spores  colorless, 
simple,  elliptical,  9/a  X  3.5yu,. 

Jf.  Lecidea  geographica.  Thallus  areolate,  alter- 
nately dark  and  yellow,  producing  a  characteris'ic 
effect  faintly  resembling  a  colored  map.     Apothecia 


112  GUIDE    TO    THE    STUDY    OF    LlCHENS. 

rather   small,    somewhat   immersed,    flattened.     Disk 
dark.     Spores  simple,  colorless,  elliptical. 


7. 

Another  insignificant  group  having  a  close  resem- 
blance to  Bilimbia  and  by  some  authors  placed  with 
Biatora.  It  differs  from  Bilimhia  in  that  the  hypo- 
thecium  is  dark.  The  genus  requires  further  careful 
study.  Only  a  few  species  are  reported.  These  occur 
upon  tree-trunks  and  moss. 

1.  Celidiopsis  platycarpa.  Thallus  rudimentary, 
granular,  gray  to  greenish.  Apothecia  small,  ele- 
vated margin.  Disk  flattened,  black.  Spores  color- 
less, rather  variable  in  size  and  form,  four-celled, 
22/x  X  V 

8.  Buelliopsis. 

This  genus  is  represented  by  a  few  species.  It  dif- 
fers from  Buellia  in  its  spore-characters,  otherwise  it 
is  the  same.  The  spores  are  four-celled,  dark,  con- 
stricted at  the  transverse  septa. 

1.  Buelliopsis  vernicoma.  Thallus  granular,  spread- 
ing, gray  to  greenish.  Apothecia  small,  elevated  mar- 
gin. Disk  flattened,  black.  Spores  dark-brown,  dis- 
tinctly four-celled,  usually  constricted  at  the  septa, 
16/x  X  6.5/x. 

9.  Buellia. 

The  Buellias  are  well  characterized,  and  are  repre- 
sented by  a  large  number  of  species.  The  general  char- 
acters of  the  thallus  resemble  those  of  Biatora  and 
Lecidea.     The  apothecia  are  medium  in  size  and  are 


GEKERA    AND    SPECIES.  113 

more  or  less  irregular  in  outline.  The  spores  are 
normally  two-celled,  constricted  at  the  middle,  dark  to 
nearly  black  in  color. 

The  BuelUas  have  a  wide  range,  and  occur  upon 
rocks,  rarely  upon  trees  and  old  fences.  They  are 
found  at  very  high  altitudes.  Formerly  the  BuelUas 
were  united  with  the  Lecideas.  Reinke  considers 
them  closely  related  to  Rinodina, 

1,  Buellia  Schcsreri.  Thallus  granular  to  indis- 
tinctly areolate,  brownish.  Apothecia  very  small. 
Disk  dark-brown  to  black.  Spores  two-celled,  dark- 
brown,  not  constricted,  ends  blunt,  12/x  X  7yM. 

2.  Buellia  parmeliarum.  Thallus  granular,  green- 
ish to  ash-gray.  Apothecia  small.  Disk  convex, 
black.     Spores  oblong,  dark-brown,  12/a  X  5/x. 

This  plant  is  said  to  be  normally  parasitic  upon 
species  of  Parmelia.  The  majority  of  plants  found 
upon  Parmelia  are,  however,  very  likely  parasitic 
fungi,  as  in  those  examined  no  thallus  could  be 
detected. 

S.  Buellia  parasema.  Thallus  granular  to  more  or 
less  irregularly  areolate,  areoles  sometimes  scattered, 
gray.  Apothecia  medium  to  large,  considerably  ele- 
vated above  the  surface  of  the  thallus.  Disk  flat- 
tened, margin  somewhat  elevated,  black.  Spores 
two-celled,  dark-brown,  not  constricted,  sometimes  nar- 
rowed at  one  end  and  slightly  curved,  14ya  X  6/x. 

4.  Buellia  dialyta.  Thallus  from  thin  and  uni- 
formly spreading  to  minutely  granular,  granules 
often  scattered,  ash-gray.  Apothecia  small,  somewhat 
elevated    above    the    thallus.     Disk    convex,   black. 


114  GUIDE    TO    THE    STUDV    OF    LICSENS. 

Spores  two-celled,  sometimes  constricted,  large,  dark- 
brown,  24/A  X  lliW" 

5.  Buellia  stellulata.  Thallus  of  rather  small,  ir- 
regular, scattered  areoles.  Apothecia  very  small,  barely 
extending  above  the  surface  of  the  thallus.  Disk  flat, 
brown  to  black.  Spores  two-celled,  not  constricted, 
ends  blunt,  9/x  X  5/x. 

6.  Buellia  Eiizce.  Thallus  of  minute,  more  or  less 
scattered  granules,  gray  to  greenish.  Apothecia  medium. 
Disk  reddish-brown  to  black.  Spores  in  various  stages 
of  development,  two-celled  and  dark-brown  when  ma- 
ture, 13/x  X  7/A. 

7.  Buellia  myriocarpa.  Thallus  thinly  granular, 
ash-gray  to  greenish.  Apothecia  small,  numerous, 
somewhat  elevated  above  the  thallus.  Disk  flat- 
tened, black.  Spores  two-celled,  dark-brown,  14/x 
X  7/.. 

8.  Buellia  colludens.  Thallus  of  very  small,  closely 
adnate,  angular  squamules  with  slightly  depressed  mar- 
gins, gray  to  brownish.  Apothecia  small,  variable  in 
form,  somewhat  elevated  above  the  thallus.  Disk  flat- 
tened, black.  Spores  two-celled,  constricted,  dark- 
brown,  lo/x  X  6.5/x. 

9.  Buellia  coracina.  Thallus  of  comparatively  large, 
rather  irregular  squamules,  with  upper  surface  more  or 
less  convex,  dark  to  nearly  black.  Apothecia  of  me- 
dium size,  adnate  upon  the  thallus.  Disk  convex,  dark 
to  black.  Spores  two-celled,  not  constricted,  dark- 
brown,  15/x  X  8yu,. 

10.  Buellia  hadia.  Thallus  of  small,  angular,  closely 
adnate   squamules,   tawny   to   brownish.      Apothecia 


GENERA    AND    SPECIES.  115 

small,  immersed.     Disk  flattened,  black.     vSpores  two- 
celled,  brownish  when  mature,  8/a  X  4.5/x. 

11.  Buellia  spuria.  Thallus  of  rather  large  angu- 
lar squamules,  somewhat  convex  above  with  dark  mar- 
gin, light  to  gray.  Apothecia  of  medium  size,  adnate, 
only  slightly  extending  above  the  thallus,  irregular  in 
form  and  size,  often  covering  the  entire  squamule,  mar- 
gin somewhat  elevated.  Disk  black.  Spores  two- 
celled,  dark-brown,  15/a  X  7/x. 

12.  Buellia  pulchella.  Thallus  well  developed,  con- 
sisting of  gyrate  folds,  resembling  the  convolutions  of 
the  brain,  greenish-yellow.  Apothecia  medium  to 
large,  sessile.  Disk  convex,  black.  Spores  two-celled, 
constricted,  dark-brown,  14/x  X  7/w,. 

10.    Catillaria. 

This  genus  requires  further  careful  study.  Tucker- 
man  and  others  included  it  in  the  uncertain  group 
Heterothecium.  Its  general  characters  resemble  those 
of  Lecidea.  The  hypothecium  is  dark-blue  to  black. 
Thallus  is  rudimentary.  The  algae  are  no  doubt  Pleu- 
rococcus.  Spores  two-celled,  large,  colorless.  Only 
one  species  from  the  United  States  has  come  to  my 
notice. 

1.  Catillaria  grossa.  Thallus  thin,  papery,  smooth, 
almost  shining.  Apothecia  medium  in  size.  Disk 
flattened,  margin  elevated,  black.  Spores  two-celled, 
colorless,  large. 

C.  grossa  occurs  upon  bark  of  ash  and  perhaps  other 
trees.  It  is  not  common,  and  nothing  definite  is  known 
concerning  its  distribution. 


116  GUIDE    TO    THE    STUDY    OF    LICHENS. 

11.  Megalospora. 

This  genus  has  also  been  included  under  Heterothe- 
cium.  Its  general  characters  are  like  those  of  Gatil- 
laria;  the  apothecia  are  somewhat  larger  and  the 
disk  more  convex.  The  thallus  presents  almost  the 
same  external  appearance  as  to  color  and  general  con- 
formation ;  the  algae  are,  however,  Protococcus  instead 
of  Pleicrococcus.  The  hypothecium  is  black  or  blue- 
black.  Each  spore-sac  contains  one,  rarely  two,  large 
simple  spores.  The  spore-wall  consists  of  two  layers, 
of  which  the  outer  one  is  quite  thick  and  gelatin- 
ous. 

1.  Megalospora  sanguinaria.  Thallus  light-gray. 
Apothecia  comparatively  large.  Disk  convex.  Spores 
large,  simple,  colorless,  outer  spore-wall  (exosporium) 
thick,  103^  X  4:0/x. 

The  above  is  the  only  species  which  came  to  my  no- 
tice. It  is  not  very  common  and  occurs  upon  trees.  It 
seems  to  be  northern  in  its  range. 

12.  Lopadium. 

This  genus  is  also  taken  from  the  conglomerate 
group  Heterothecium.  The  thallus  is  crustose  and  uni- 
formly spreading.  The  algae  are  Chroolepus  umhrina. 
Soralia  are  common.  The  apothecia  are  of  medium 
size,  loosely  sessile  upon  the  thallus,  discoid.  A  red- 
dish-brown or  nearly  black  color  pervades  almost  the 
entire  apothecial  structure.  The  spores  are  multiloc- 
ular,  large,  and  vary  from  colorless  to  brown  and  red- 
dish-brown. 

A  few   species   are   reported   which   seem    to    be 


GENERA    AND    SPECIES.  117 

southern  in  their  range.     They  occur  upon   trees  and 
mosses. 

1.  Lopadium  pezizoideum.  Thallus  granular,  uni- 
formly spreading,  thin,  grayish.  Apothecia  of  medium 
size,  discoid,  not  numerous.  Disk  convex,  dark.  Spores 
large,  one  in  each  spore-sac,  colorless,  and  simple  in 
early  stages  of  development,  multilocular  and  dark 
when  mature,  90/x  X  35/a. 

13.    Gyalecta. 

This  is  one  of  the  older  genera,  and  hence  it  would 
bfi  reasonable  to  assume  that  it  is  well  understood,  but 
such  is  not  the  case.  A  large  number  of  herbarium 
specimens  labelled  as  Gyahctas  belong  to  other  gen- 
era. It  is  in  fact  impossible  at  the  present  to  give 
the  exact  limitations  of  the  genus.  The  following 
are  some  of  the  generic  characters,  as  far  as  they 
could  be  determined. 

The  thallus  is  crustose  in  the  majority  of  species ; 
becoming  minutely  foliose  in  the  higher  species, 
color  generally  dark.  The  algie  are  Protococcus, 
Apothecia  are  discoid.  Disk  is  flattened  to  some- 
what cup-shaped,  dark.  The  hypothecium  is  usually 
colorless.  The  spores  are  quite  large  and  multilocu- 
lar, oblong  to  spindle-shaped,  usually  colorless,  though 
some  are  evidently  dark  in  color. 

They  occur  upon  rock  and  trees.  Nothing  definite 
can  be  stated  as  regards  range  and  frequency  of  occur- 


rence. 


1.    Gyalecta   cupularis.      Thallus    crustose,  evenly 
spreading,   gray   to  dark.     Apothecia  discoid.     Disk 


118  GUIDE    TO    THE    STUDY    OF    LICHENS. 

concave,    reddish-brown,    margin     somewhat     rugose. 
Spores  multilocular,  somewhat  colored  when  mature, 

40/A  X  20/x. 

IJf.  Psora. 

By  some  authors  this  genus  is  classed  with  Biatora, 
others  class  it  with  Lecanora.  It  is  the  first  group 
of  the  LecideacecB  in  which  the  thallus  is  typically 
foliose.  The  thallus  is  simple,  entire,  small,  and  is 
usually  closely  adnate  to  the  substratum,  or  the  entire 
lobes  may  be  plicate  or  ascending.  The  lobes  never 
became  large,  scarcely  exceeding  one-fourth  of  an 
inch  in  diameter.  They  are,  however,  comparatively 
thick,  thus  giving  them  considerable  rigidity.  Their 
color  is  quite  variable  ;  the  upper  surface  varies  from 
light-gray  to  black  ;  the  lower  surface  is  usually  of  a 
lighter  color. 

The  apothecia  are  small  to  medium,  distributed 
over  the  thallus,  but  sometimes  ranged  about  the 
margin.  They  are  somewhat  discoid  and  more  or  less 
immersed  in  the  thallus.  The  disk  is  dark-colored 
(rusty).  The  spores  are  simple,  elliptical,  colorless, 
closely  resembling  those  of  Biatora. 

The  Psoras  occur  upon  rock  and  soil ;  they  seem  to 
be  quite  generally  distributed. 

1.  Psora  icteria.  Thallus-lobes  rather  small, 
scarcely  ascending,  margin  somewhat  crenate  and 
light  colored ;  upper  surface  greenish  becoming 
tawny  with  age  ;  light  colored  beneath.  Apothecia 
rather  small,  sessile.  Disk  nearly  black.  Thecium 
and  hypothecium  yellowish.  Spores  simple,  color- 
less, elliptical,  16/x  X  7/x. 


GENERA    AND    SPECIES.  119 

2.  Psora  atro-rufa.  Thallus  of  rather  small  lobes, 
margin  more  or  less  crenate  and  lobulate,  closely 
adnate  to  the  substratum,  color  dark.  Apothecia 
medium,  sessile,  disk  slightly  convex,  dark.  Spores 
simple,  colorless,  elliptical,  14/a  X  5/x. 

3.  Psora  rufonigra.  Thallus-lobes  rather  small, 
somewhat  ascending,  margin  wavy  and  lobulate, 
upper  surface  dark  reddish-brown  to  nearly  black. 
Apothecia  medium  to  large,  marginal.  Disk  convex, 
black.     Spores  colorless,  simple,  elliptical,  12/x  X  'V- 

4.  Psora  decipiens.  Thallus-lobes  usually  ascend- 
ing, closely  crowded,  margin  more  or  less  crenulate, 
lobed,  turned  back  and  white  ;  upper  surface  brown 
to  tawny  ;  white  beneath.  Apothecia  much  as  in  P. 
icteria.     Spores  simple,  colorless,  elliptical,  14/x  X  C/x. 

5.  Psora  RusselUi.  Thallus-lobes  rather  large, 
entire,  quite  thick  and  rigid,  margin  somewhat  cre- 
nate, white,  slightly  turned  up  ;  upper  surface  brown- 
ish, lower  surface  light  color.  Apothecia  of  medium 
size,  usually  marginal.  Disk  convex,  brown.  Spores 
simple,  colorless,  elliptical,  11/x  X  4.5/a. 

15.    Gyrophora. 

The  representatives  of  this  genus  are  highly  inter- 
esting, both  as  to  size  and  form  and  as  to  the  eco- 
nomic uses  to  which  they  have  been  put  in  the  past. 

The  thallus  is  typically  foliose,  and  varies  in  size 
from  medium  to  very  large.  The  smaller  thalli  may 
either  be  single  or  form  a  cluster,  more  or  less  imbri- 
cate. No  matter  what  the  size  of  the  thallus  may  be, 
it  is    always    entire   and   held  to  the    substratum  by 


120  GUIDE    TO    THE    STUDY    OF    LICHENS. 

the  umbilicus.  The  margin  is  generally  somewhat 
torn.  The  prevailing  color  of  the  upper  surface  is 
gray  to  nearly  black ;  the  lower  surface  is  quite 
black,  bearing  black  rhizoids  or  scaly  lamina. 

The  apothecia  are  rather  peculiar  in  structure. 
They  are  sessile  upon  the  thallus,  and  on  examina- 
tion with  a  pocket-lens  the  disk  presents  a  convo- 
luted appearance,  reminding  one  of  the  convolutions 
of  the  dentine  in  the  tooth  of  a  ruminant.  The  disk 
is  convex,  black.  The  spores  are  simple,  elliptical, 
colorless. 

The  Gyrophoras  are  northern  in  their  range,  but 
are  also  quite  common  in  the  mountainous  regions  of 
the  temperate  and  torrid  zones.  They  grow  upon 
rock  and  soil.  Quite  generally  this  group  is  com- 
bined with  Umhilicaria. 

1.  Gyrophora  hyperhorea.  Thallus  medium,  nearly 
entire,  margin  somewhat  incised  and  torn,  rugose 
above,  dark  to  black;  usually  smooth  and  some- 
what lighter  below.  Apothecia  small  to  medium.  Disk 
flattened,  black.  Spores  ovoid,  colorless,  somewhat 
curved,  14/x  by  7/u,. 

2.  Gyrophora  prohoscidea.  Thallus  medium  size, 
somewhat  lobed  or  folded,  and  rugose  above,  margin 
torn  and  occasionally  perforate,  bearing  cilia,  gray, 
dark  near  margin ;  lower  surface  pale  toward  centre, 
becoming  darker  toward  margin.  Apothecia  of  me- 
dium size,  scattered  over  the  thallus,  except  at  the 
centre  and  margin.  Disk  flattened,  black.  Spores 
simple,  colorless,  elliptical  or  ovoid,  slightly  curved, 
16ft  X  7ft. 


GENERA    AND    SPECIES.  121 

According  to  Porcher,  Icelanders  use  this  lichen  as 
an  article  of  food  ;  more  frequently  for  dyeing  woollen 
cloth  a  brownish-green  color. 

3.  Gyrophora  erosa.  Thallus  medium  in  size,  more 
or  less  lobed,  margin  ragged  and  reticulately  perforate, 
entire  upper  surface  more  or  less  reticulate,  dark  color ; 
lower  surface  fissured,  areolate,  lighter  than  upper  sur- 
face. Apothecia  small.  Disk  convex,  black.  Spores 
small,  colorless,  granular,  lO/x  X  4.5/x. 

4.  Gyrophora  floculosa.  Thallus  small  to  medium, 
thin,  margin  somewhat  lobed  and  torn  ;  upper  surface 
dark-brown,  bearing  numerous  fine  thalloid  outgrowths  ; 
lower  surface  of  nearly  the  same  color  and  reticulately 
veined.     No  fertile  specimens  have  come  to  my  notice. 

5.  Gyrophora  Muhlenhergii.  Thallus  medium  to 
large,  margin  more  or  less  torn  ;  upper  surface  smooth, 
pitted  and  rugosely  folded,  ash-gray,  darker  toward 
the  margin ;  lower  surface  more  or  less  reticulate, 
fringed  toward  the  margin,  dark-brown.  Apothecia 
from  medium  to  large,  situated  in  pits,  scattered  toward 
the  margin  of  thallus.  Disk  convex,  black.  Spores 
simple,  elliptical,  colorless,  10/x,  X  5^. 

This  is  one  of  the  lichens  known  as  "  tripe  de  roche," 
and  was  used  by  Sir  John  Franklin  on  his  journey  to 
the  polar  seas.  It  was  said  to  be  "  agreeable  and  nu- 
tritious," although,  like  other  lichens,  it  contains  an 
objectionable  bitter  principle. 

6.  Gyrophora  vellea.  Thallus  large,  entire,  margin 
more  or  less  incised  and  somewhat  broken  or  torn, 
upper  surface  smooth  or  finely  powdered,  gray  ;  lower 
surface  brown  to  dark,  bearing  numerous  rigid  cilia. 


122  GUIDE    TO    THE    STUDY    OF   LICHENS. 

Apothecia  in  slight  depressions  of  thallus,  marginal, 
small  to  medium.  Disk  convex,  black.  Spores  sim- 
ple, colorless,  elliptical,  slightly  granular,  10/x  by  7/x. 

"  Some  varieties  of  this  species  are  imported  to  a 
considerable  extent  into  the  London  market  from  the 
Norwegian  mountains,  for  the  manufacture  of  orchill 
and  cudbear,  under  the  name  of  *  Norway  rock  moss/ 
or  'velvet  or  velutous  moss.'  Like  most  of  its  co- 
species,  it  grows  chiefly  on  granitoid  rocks  on  very 
high  mountains,  or  in  arctic  or  sub-arctic  regions.  On 
the  Mexican  volcano  of  Orizabo  it  occurs  at  a  height 
of  between  13,000  and  14,000  feet,  along  with  other 
species.  This  is  another  of  the  lichens  which  consti- 
tute the  '  tripe  de  roche  '  of  sub-arctic  America  and  the 
polar  regions.  This  black,  leathery,  forbidding-look- 
ing '  rock- tripe  '  is  often  boiled  and  eaten  by  the  Cana- 
dian hunter  when  pressed  by  hunger.  In  Iceland  it  is 
frequently  eaten  in  periods  of  scarcity  as  a  supplement 
to  the  more  nutritious  '  Iceland  moss ' ;  and  it  has 
been  frequently  mentioned  in  the  narrative  of  the 
polar  voyages  as  having  been  the  means  of  saving  the 
crew  from  perishing  by  starvation.  The  nutritive 
properties  of  these  lichens  depend  on  the  presence  of 
a  large  amount  of  starchy  matter  (lichenin,  lichen- 
starch).  "When  boiled  they  yield,  like  Cetraria  Island- 
ica,  a  firm,  nutrient  jelly,  which  is,  however,  accom- 
panied, as  in  that  lichen,  by  a  bitter  principle  possessed 
of  purgative  properties.  Linnaeus  speaks  of  some  Gy- 
rophoras  as  superior  in  nutritive  qualities  to  the  '  Ice- 
land moss.'  "  —  Lindsay. 

7.   Gyrophora    Dillenii.      Thallus    large    to    very 


GENERA   AND    SPECIES.  123 

large,  entire,  margin  somewhat  lobed  or  torn  ;  upper 
surface  smooth,  centre  raised,  gray  to  brown;  lower 
surface  dark.  Apothecia  medium  to  large,  scattered, 
convex,  black.  Spores  large,  colorless,  simple,  very 
granular,  ovoid,  not  curved,  24/x  X  12/x. 

16.    Umhilicaria. 

The  general  appearance  and  structure  of  the  thallus 
and  apothecia  of  Umhilicaria  shows  its  close  relation- 
ship to  Gyrophora.  It  differs,  however,  in  that  rhi- 
zoids,  cilia  and  scaly  plates  (lower  surface)  are  want- 
ing. Coloration  is  the  same  in  both.  In  Umhilicaria 
the  thallus  is  more  or  less  pustular.  The  important 
distinguisliing  characters  occur  in  the  spores,  wliich  in 
this  genus  are  large,  brown-colored,  multilocular,  each 
spore-sac  bearing  a  single  spore. 

The  algae  in  Gyrophora  and  Umhilicaria  are  evi- 
dently Protococcus,  though  they  differ  in  form  from 
those  occurring  in  other  lichens  ;  further  investigation 
may  prove  it  another  alga. 

The  range  and  habitat  of  this  group  is  much  as 
that  of  the  preceding.  It  is  represented  by  fewer  spe- 
cies. When  dry,  these  lichens  are  very  brittle,  hence 
the  collector  will  find  it  necessary  to  gather  them 
when  the  atmosphere  is  moist,  or  to  pour  water  upon 
them  before  attempting  to  remove  them  from  the  rock 
upon  whicli  they  grow. 

1  Umhilicaria  papulosa.  Thallus  medium  to 
large,  thin,  margin  more  or  less  lobate  and  torn; 
pustular,  pustules  quite  separate  and  uniform  in  size ; 
dark-gray  above;    lower    surface    reticulately  pitted. 


124  GUIDE    TO    THE    STUDY    OF    LICHENS. 

smooth,  colored  much  as  upper  surface.  Apothecia 
small,  scattered  over  greater  portion  of  thallus. 
Disk  flattened,  black.  Spores  one,  rarely  two, 
light-brown  to  dark-brown,  multilocular,  elliptical, 
71/Lt  X  3V 

2.  Umhilicaria  Pennsylvanica.  Thallus  medium 
to  large,  thin,  more  or  less  wavy,  margin  somewhat 
torn ;  pustules  much  as  in  U.  papulosa ;  dark-gray 
above ;  black  and  reticulately  fitted  below.  Apothe- 
cia large,  elevated  margin.  Disk  flat,  black.  Spores 
68/x,  X  27/x,  otherwise  as  in  U.  papulosa. 

3.  Umhilicaria  pustulata.  Resembles  U.  papulosa 
with  the  exception  that  the  pustules  are  larger,  con- 
fluent; lower  surface  more  reticulately  pitted.  Apo- 
thecia more  numerous  and  showing  a  tendency  to 
coalesce.     Spores  as  in  U.  papulosa. 

"  According  to  Linnasus,  a  beautiful  red  color  may 
be  prepared  from  this  lichen,  and  it  may  be  converted 
into  '  an  exceeding  fine  black  paint '  "  — Porcher. 

IV.  GRAPHIDACEyE. 

In  all  probability  the  family  is  out  of  its  natural 
position  as  here  given.  The  reason  that  it  is  placed 
above  the  LecideacecB  is  because  it  was  believed  that 
Rocella  should  be  included  in  the  family,  in  accord- 
ance with  the  views  held  by  Reinke.  It  is,  however, 
probable  that  Rocella  belongs  to  the  Parmeliacece. 
If  the  exclusion  is  admitted,  the  Graphidacece  are 
lowly  organized  lichens,  in  which  the  thallus  never 
develops  beyond  the  crustose  stage,  and  hence  the 
family  would  really  be  placed  before  the  Caliciacece, 


GENEKA    AND    SPECIES.  125 

The  present  classification  will,  however,  be  retained, 
although  RoceMa  will  be  included  under  Parmeliacece. 
The  Graphidacece  are  essentially  southern  in  their 
range,  where  they  also  attain  their  maximum  devel- 
opment ;  particularly  is  this  true  of  Graphis  and 
Arthonia.  The  thallus  is  crustose  and  quite  variable 
in  color  and  thickness.  In  a  large  per  cent,  of  the 
representatives  the  thallus  is  hypophloeodal,  that  is,  it 
occurs  below  the  surface  of  the  substratum  and  is 
therefore  invisible  to  the  naked  eye.  The  apothecia 
are  characteristic  ;  instead  of  being  discoid,  as  in  the 
majority  of  lichens,  they  are  linear,  stellate  or  ir- 
regular in  outline.    They  belong  to  the  fungal  type. 

KEY   TO   THE   GENERA. 

Spores  two  to  eight-celled  or  simple,  colorless. 

Two-celled 1.  Hazslinskya. 

Four  to  six-celled,  elliptical 2.  Onegrapha. 

Eight-celled,  large,  oblong,  curved   .     .     .  3.   Graphis. 

Simple 4.  Xijlographa. 

Four-celled,  one  end  narrowed      ....  5.  Arthonia^ 
Spores  multilocular. 

Constricted  in  the  middle 6.  Mycoporum. 

Not  constricted,  colorless 7.  Art hothel turn. 

1.  Hazslinskya. 

A  lowly  organized  group  having  only  a  few  repre- 
sentatives. The  thallus,  as  well  as  the  apothecia, 
begin  their  development  below  the  surface  of-  the  sub- 
stratum. The  algae  are  Chroolepus.  The  apothecia 
soon  break  through  and  appear  as  minute  black  dots  ; 
upon  examination  with  a  lens  they  are  seen  to  be 
more  or  less  orbicular  or  somewhat  elongated,  with 
1  Some  of  the  southern  Arthonias  have  colored  spores. 


126  GUIDE    TO    THE    STUDY    OF    LICHENS. 

irregular  outline.  The  disk  *  is  flattened  and  dark  in 
color.  The  spores  are  colorless,  of  medium  size,  two- 
celled  ;  one  cell  larger,  constricted  at  the  septum. 

1.  Hazslinskya  demissa.  Thallus  partly  below  the 
substratum,  rudimentary,  light  color.  Apothecia 
oval,  irregular  in  outline  ;  single,  not  in  groups,  as  in 
the  European  form  H.  gibherulosa^  opening  by  an 
oval  pore.  Disk  dark.  Spores  colorless,  two-celled, 
constricted  at  the  septum,  one  cell  larger,  17/a  X  8/x. 

This  lichen  is  usually  classified  as  Opegrapha  de- 
missa. 

2.    Opegrapha. 

Thallus  rudimentary  and  mostly  hypophloeodal, 
finally  forming  a  thin  film  over  the  substratum. 
The  algae  are  Chroolepus.  The  apothecia  are  usually 
numerous,  small,  linear,  more  or  less  curved,  pro- 
jecting somewhat  above  the  surface  of  the  substratum. 
Disk  black.  The  hypothecium  is  also  black.  The 
spores  are  colorless,  elliptical  to  almost  acicular,  usu- 
ally four-celled.     They  occur  upon  trees. 

1.  Opegrapha  varia,  Thallus  finely  pulverulent, 
light-colored,  mostly  hypophoeodal.  Apothecia  ellip- 
tical, oblong  to  short-linear.  Disk  black.  Spores 
are  four  to  six-celled,  colorless  to  pale  yellow, 
23/x  X  2.5/x. 

2.  Opegrapha  vulgata.  Thallus  rudimentary,  whit- 
ish. Apothecia  elliptical  to  distinctly  linear,  rather 
small.  Spores  acicular,  indistinctly  four  to  six- 
celled,  colorless,  24/x  X  2.5/x. 

1  The  term  "  disk  "  is  scarcely  applicable  to  the  irregular  apothecia 
of  this  family,  but  will  be  retained  to  avoid  the  necessity  of  intro- 
ducing a  new  term. 


I'LA'i'K  Ir(.  Cnistose  Types.  From  i\\v  coiit'cuoii  ni  X. 
V.  (lark  ill  ilic  lit'ibariiim  of  Llie  Calit'oniiu  Academy  «'t 
Science.      li'rdiiJiis  scrijiln. 


GENERA    AND    SPECIES.  127 

3.    Graphis. 

This  gBDus  is  well  represented  in  the  southern 
states.  The  thallus  is  always  crustose,  though  it  may 
attain  considerable  thickness.  The  thallus,  as  well  as 
the  apothecia,  begins  development  below  tlie  surface 
of  the  substratum,  but  soon  breaks  through  after  which 
the  thallus  rapidly  spreads.     The  algae  are  Chroolepus. 

The  apothecia  are  distinctly  linear,  often  branching, 
bent  or  angular.  The  disk  is  black  in  the  northern 
species,  black  or  white  in  the  southern  forms.  The 
color  of  the  thallus  also  varies  from  greenish-gray  to 
white.  The  spores  are  comparatively  large,  six  to 
twelve-celled,  colorless,  somewhat  curved ;  the  more  or 
less  gelatinous  exosporium  is  wavy  in  outline. 

The  species  occur  upon  trees,  preferably  the  smoother 
barks. 

1.  Graphis  elegans.  Thallus  hypophloeodal.  Apo- 
thecia linear,  branching,  prominent.  Disk  black.  Usu- 
ally sterile. 

This  lichen  closely  resembles  G.  scripta  and  is,  per- 
haps, merely  a  varietal  form  of  that  species. 

2.  Grapliis  scripta.  Thallus  hypophloeodal.  Apo- 
thecia as  in  G.  elegans,  less  prominent.  Spores  eight- 
celled,  colorless,  variable  in  size,  34/x,  X  H/^* 

This  lichen  is  common  everywhere. 

3.  Graphis  dentritica.  Thallus  rarely  becoming 
epiphloeodal  at  maturity.  Apothecia  radially  linear 
and  branching.  Disk  black.  Spores  colorless,  usually 
eight-celled,  one  end  often  narrowed,  24/x  X  6.5/x. 

4'  Graphis  eulectra.  Thallus  soon  becomes  epi- 
phloeodal, light-gray  to  nearly  white,  evenly  spreading. 


128  GUIDE    TO    THE    STUDY    OF    LICHENS. 

smooth.  Apothecia  linear,  branching,  partially  en- 
closed by  the  thallus.  Spores  colorless,  eight-celled, 
30/x  X  8.5^. 

Jf..   Xylographa. 

The  thallus  begins  its  development  below  the  sur- 
face of  the  substratum,  finally  spreading  over  the  sur- 
face in  the  form  of  a  thin  whitish  layer.  The  algae 
0,re  Chroolepus  and  Protococcus.  The  apothecia  are 
linear  or  irregular,  extending  parallel  to  the  fibres  of 
the  woody  substratum.  The  disk  is  dark.  The  hypo- 
thecium  is  nearly  colorless.  The  spores  are  rather 
small,  simple,  elliptical,  colorless  and  usually  sparingly 
present. 

They  occur  upon  rotten  logs  and  bark  of  trees. 

1.  Xylographa  parallella.  Thallus  becomes  epi- 
phloeodal  at  an  early  period,  smooth,  uniform,  light- 
gray.  Apothecia  linear,  extending  parallel  to  the  fibres 
of  the  wood.  Disk  dark.  Spores  simple,  colorless, 
ovoid,  15/x  X  6.5/x. 

This  plant  occurs  upon  rotten  logs,  and  is  character- 
istic in  appearance.     The  algae  are  Protococcus. 

2,  Xylographa  opegraphilla.  Thallus  soon  becomes 
epiphloeodal,  distinct,  areolate,  areoles  easily  removed, 
pale-gray.  Apothecia  short-linear,  rarely  branching. 
Disk  pale-brown  to  dark.  Spores  simple,  ovoid, 
colorless,  14/x  X  6yu,. 

In  this  lichen  the  algae  are  Chroolepus. 

5.  Arthonia. 
This  is  in  many  respects  a  difficult  group  for  study, 
principally  because  its  representatives    are  numerous 


GENERA    AND    SPECIES.  129 

and  lowly  organized.  The  difficulty  is  increased  by 
the  fact  that  many  species  are  generally  sterile,  that 
is,  they  are  without  spores  though  apothecia  may  be 
present.  Tlie  thallus  is  deficient  and  the  algal  charac- 
ters are  variable  ;  in  some  cases  it  is  evidently  Chroo- 
lepus,  in  others,  Protococcus.  Further  investigation 
may  make  it  advisable  to  subdivide  the  group  upon 
these  algal  differences. 

The  apothecial  characters  are  also  variable.  Along 
with  the  thallus,  the  apothecia  begin  their  development 
below  the  surface  of  the  substratum,  breaking  through 
some  time  before  maturity ;  rarely  they  remain  cov- 
ered over  by  a  thin  layer  of  the  thallus  and  substra- 
tum. They  are  small,  irregular  in  outline,  never 
distinctly  linear ;  sometimes  they  are  stellate  or  tend 
to  become  linear,  with  radiating  projections.  The 
disk  and  hypothecium  are  dark,  sometimes  reddish- 
brown. 

The  spores  are  characteristic  in  form ;  they  are  ob- 
long, either  colorless  or  dark-colored,  usually  four- 
celled,  the  ends  blunt,  narrowed  toward  one  end  caus- 
ing it  to  resemble  the  outline  of  the  sole  of  a  shoe. 

The  Arthonias  are  southern  in  their  range,  though 
less  so  than  Graphis.     Tkey  occur  upon  trees. 

1.  Arthonia  astroidea.  Thallus  indistinct,  mostly 
hypophloeodal.  Apothecia  numerous,  irregular,  stel- 
late, sometimes  somewhat  elongated ;  only  sliglitly 
raised  above  the  substratum  (bark).  Disk  black. 
Spores  colorless,  four-celled,  12/u,  X  5^. 

2.  Arthonia  dispersa.  Resembling  A.  astroidea ; 
the  apothecia  are  fewer  and  more  scattered. 


130  GUIDE    TO    THE    STUDY    OF    LICHENS. 

Species  of  Nostoc  and  Sirosiphon  (S.  pulvinatus) 
occur  parasitically  upon  many  of  the  Arthonias. 

3.  Arthonia  quintaria.  Thallus  rudimentary,  partly 
hypophloeodal,  evenly  spreading,  light-gray.  Apothe- 
cia  small,  irregular  to  somewhat  linear,  scattered. 
Spores  colorless,  four  to  seven-celled,  somewhat  curved, 
narrowed  toward  one  end,  24/u,  X  7/x. 

4.  Arthonia  tcediosa.  Thallus  rudimentary,  partly 
hypophloeodal,  evenly  spreading,  extending  over  the 
apothecia  in  the  form  of  a  thin  film,  light  color  to  green- 
ish. Apothecia  medium,  numerous,  irregularly  stel- 
late. Disk  dark.  No  spores  came  to  my  notice.  The 
spore-sacs  were  either  entirely  empty  or  contained  only 
immature,  gelatinized  spores. 

5.  Arthonia  radiata.  Thallus  much  as  in  A.  quin- 
taria.  Apothecia  more  numerous,  larger,  irregularly 
stellate.     Spores  colorless,  four-celled,  17ft,  X  4.0/x. 

6.  Arthonia  punctiformis.  Thallus  rudimentary, 
partly  hypophloeodal,  evenly  spreading,  light-gray. 
Apothecia  very  small,  irregular  in  form.  Disk  dark. 
No  mature  spores  came  to  my  notice. 

7.  Arthonia  polymorpha,  Thallus  partly  hypoph- 
loeodal, evenly  spreading,  pale  color.  Apothecia  of 
very  irregular  outline,  thinly  overspread  by  the  thal- 
lus.    Disk  dark-brown.     No  spores  seen. 

8.  Arthonia  lecidella.  Thallus  distinct,  irregularly 
areolate,  light  bluish-green  (  Chroolepus  and  Protococ- 
cus  both  present).  Apothecia  rounded,  slightly  raised. 
Disk  somewhat  convex,  dark.  Spores  as  in  A.  as- 
troidea. 

9.  Arthonia  glahrata.    Thallus  quite  distinct,  some- 


Genera  and  species.  131 

what  areolate,  grayish  in  color,  partially  enclosing  the 
apothecia.  Apothecia  comparatively  large,  irregular 
in  outline.     Disk  dark.     Spores  not  seen. 

10.  Arthonia  atra.  Thallus  rudimentary,  mostly 
hypophl(]eodal,  light  color.  Apothecia  numerous, 
oblong  to  linear  or  branching.  Disk  dark.  Spores 
typical,  16/x  X  4:.5/x. 

11.  Arthonia  varia.  Thallus  rudimentary,  light- 
gray.  Apothecia  distinct,  linear,  not  branching. 
Spores  typical,  15/x  X  3/x. 

6.  Mycoporum. 

This  is  a  small  group  whose  position  is  rather  un- 
certain. It  is  evidently  closely  related  to  the  Graphid- 
acecB. 

The  thallus  is  rudimentary  and  begins  its  develop- 
ment below  the  surface  of  the  substratum.  It,  how- 
ever, soon  breaks  through,  forming  a  deficient  crus- 
tose  thallus.  The  algae  are  perhaps  Protococcus, 
though  they  also  have  a  resemblance  to  Pleurococus. 

The  apothecia  are  irregular  in  outline  but  never 
distinctly  linear.  Disk  and  hypothecium  are  black. 
The  spores  are  large,  eight  in  number,  multilocular, 
colorless  to  brownish,  and  constricted  at  the  middle. 

The  few  representatives  occurring  in  the  United 
States  seem  to  be  southern  in  their  range,  occurring 
upon  trees. 

1.  Mycoporum  pycnocarpum.  Thallus  deficient, 
evenly  spreading,  grayish.  Apothecia  small,  scat- 
tered, irregular  in  outline,  scarcely  raised  above  the 
thallus    and   substratum.     Spores  large,  multilocular, 


132  GUIDE    TO    THE    STUDY    OF    LICHENS. 

colorless    to   brown,  constricted   at    the    middle,  84/u 
X  40^. 

7.  Arthothelium. 

This  group  is  usually  associated  with  Arthonia. 
It  also  resembles  Mycoporum  in  many  respects. 

The  thallus  is  rudimentary,  often  indistinctly  areo- 
late,  grayish  to  dark  in  color.  The  algae  are  Ghroo- 
lepus.  The  apothecia  are  comparatively  large,  stel- 
late. The  disk  is  dark.  The  entire  thecium  and 
hypothecium  may  be  dark  ;  again  it  is  found  to  be 
colorless. 

The  spores  resemble  those  of  Mycoporum,  but  dif- 
fer in  that  they  are  colorless  and  not  constricted  at 
the  middle.  Each  spore-sac  bears  eight  spores,  which 
is  uncommon  with  lichens  bearing  such  large  spores. 

The  Arthothelias  are  southern  in  their  range.  They 
occur  upon  trees,  most  frequently  upon  hickories. 

1.  Arthothelium  spectahile.  Thallus  rudimentary, 
areolate.  Apothecia  numerous,  comparatively  large, 
irregular,  stellate.  Disk  black.  Spores  large,  multi- 
locular,  colorless,  78/a  X  4:0/*. 

V.    PHYSCIACE^. 

The  representatives  of  this  family  are  characterized 
by  the  two-celled  spores  in  which  the  protoplasmic  con- 
tents are  joined  by  a  slender  thread,  a  characteristic 
not  noticeable  in  spores  of  any  other  lichen-group. 

The  thallus  varies  from  typically  crustose  to  foliose 
and  fruticose,  and,  as  is  natural  to  suppose,  it  is  varia- 
ble in  size,  though  it  never  attains  any  very  great 
dimensions.     The   foliose   forms    are   often  mistaken 


GENERA    AND    SPECIES.  133 

for  species  of  Parmelia^  otherwise  there  is  little  dif- 
ficulty in  recognizing  the  Physciacece. 

The  apothecia  belong  to  the  thalline  type,  that  is 
the  algaB  of  the  thallus  enter  into  its  structure  ;  they 
are  discoid,  rarely  immersed,  the  disk  is  flattened  or 
concave,  sometimes  convex. 

The  Physciacece  seem  to  be  better  adapted  to  re- 
sist extremely  dry  periods  than  most  lichens.  They 
are  rich  in  deposits  of  lichenic  acids,  which  cause 
some  of  the  characteristic  colorations  in  thallus  and 
apothecia. 

KEY  TO   THE   GENERA. 

Thallus  crustose,  areolate,  margin  often  lobed. 

Spores  brown,  thallus  not  bright-yellow  .  1.  Rinodince. 

Spores  colorless,  thallus  yellow  to  orange,  2.  Placodium. 
Thallus  foliose,  gray,  not  yellow. 

Hypothecium  dark 3.  Pyxlne. 

Hypothecium  colorless 4.  Physcia. 

Thallus  foliose  to  fruticose,  often  yellowish,  5.  Theloschistes. 

1.  Rinodina. 

This  genus  represents  the  lowest  group  of  the 
Physciacece,  The  thallus  is  typically  crustose,  gray 
or  greenish  in  most  species ;  in  R.  oreina  the  thallus 
is  of  pale  dirty  lemon  or  sulphur  color ;  in  R.  chryso- 
melcena  there  is  also  a  marked  yellowish  tinge.  In 
some  species  a  tendency  toward  the  foliose  type 
is  noticeable.  Usually  the  thallus  is  distinctly 
areolate  and  closely  aduate  to  the  substratum.  The 
areoles  are  bounded  by  a  thin  black  zone  which  some 
authors  designate  as  the  "  hypothallus." 

The  apothecia  are  immersed  or  sessile.  In  the  ses- 
sile forms  the  thalloid  margin  extends  somewhiU  above 


134  GUIDE    TO    THE    STUDY    OF    LICHENS. 

the  disk.  In  the  immersed  apothecia  the  disk  is  ir- 
regular in  outline.  The  spores  are  dark  in  the  major- 
ity of  species.  The  algae  are  Protococcus  (excepting 
R.  oreina). 

The  Rinodinas  are  quite  common  throughout  the 
United  States,  but  have  a  slight  western  and  southern 
tendency.  They  occur  uj^on  rock  and  bark,  less  com- 
monly upon  soil  and  moss. 

1.  Rinodina  constans.  Thallus  thin,  evenly  spread- 
ing, granular  to  areolate,  grayish-green.  Apothecia 
small  to  medium.  Thalloid  exciple  slightly  raised 
above  the  dark  disk.     Spores  brown,  17/x,  X  8.5/x.^ 

2.  Rinodina  Bishoffii.  Thallus  varies  from  thinly 
granular  to  quite  thick  and  indistinctly  areolate,  brittle, 
closely  adnate  though  readily  removed,  often  leaving 
the  apothecia  behind.  Apothecia  rather  small,  slightly 
raised  above  the  thallus.  Disk  flattened,  black.  Spores 
dark-brown,  connecting  thread  often  indistinct,  sep- 
tum thick,  17/x  X  12/A. 

3.  Rinodina  sophodes.  Thallus  of  rather  indistinct, 
more  or  less  scattered,  irregular  areoles,  grayish-green 
above,  dark  beneath.  Apothecia  small.  Thalloid 
exciple,  usually  deficient.  Disk  black.  Spores  brown, 
slightly  constricted  at  the  middle,  22/x  X  8/x. 

J/..  Rinodina  oreina,  Thallus  distinctly  areolate, 
comparatively  thick,  lemon  or  sulphur  color.  Apothe- 
cia immersed,  small  to  medium.  Disk  black  or  dark- 
brown.  Spores  dark-brown,  connecting  thread  not  vis- 
ible, septum  thick,  somewhat  constricted,  10/x  X  6.5/a. 

1  Other  generic  spore-charactera  .are  given  in  the  family  descrip- 
tion, which  see. 


GENERA    AND    SPECIES.  135 

This  lichen  has  been  made  the  basis  of  the  distinct 
genus  {Dimelcena).  Its  spore-characters  closely  re- 
semble those  of  Buellia.  It  occurs  typically  upon 
granitic  rock. 

5.  Rinodina  chrysomelcena.  Thallus  rather  thick, 
irregularly  areolate,  margin  indistinctly  lobulate  ;  yel- 
lowish-green above,  black  beneath.  Apothecia  small, 
margin  elevated  above  the  dark  flattened  disk.  Spores 
dark-brown,  connecting  thread  distinctly  visible,  25^ 
X  11/x. 

6.  Rinodina  turfacea.  Thallus  verrucose  (warty), 
more  or  dess  branching,  grayish-green.  Apothecia 
from  small  to  medium  in  size,  margin  extending  slightly 
above  the  dark  flattened  disk.  Spores  brown,  slightly 
constricted  at  septum,  25.5/x  X  12/x. 

2.  Placodium. 

The  representatives  of  this  genus  are  characterized 
by  the  orange  coloration  of  the  apothecial  disk.  The 
thallus  varies  from  typically  crustose  to  distinctly  foli- 
ose,  though  it  never  attains  any  great  size ;  in  color  it 
is  usually  yellow  or  orange,  rarely  gray  to  dark.  The 
yellow  color  is  due  to  the  deposition  of  crystals  of 
chrysophanic  acid. 

The  apothecia  are  discoid,  of  medium  size,  sessile, 
with  a  distinct  thalline  margin.  The  spores  are  color- 
less, with  terminal  plasmic  masses  connected  by  a  slen- 
der plasmic  thread.  The  transverse  septum  is  not  dis- 
tinct, as  in  Rinodina ;  rarely  are  the  spores  simple. 

The  distribution  of  the  Placodias  is  much  as  that  of 
Rinodina,    They  occur  upon  rock,  also  upon  bark,  fences 


136  GUIDE    TO    THE    STUDY    OF    LICHENS. 

and  old  buildings.     Some  of  the  species  are  confused 
with  Theloschistes. 

1.  Placodium  ferrugineum.  Thallus  granular  and 
indistinctly  areolate,  variable  shades  of  gray.  Apothe- 
cia  medium,  margin  scarcely  raised.  Disk  flattened, 
rusty-brown  to  black.     Spores  typical,  17 fx  X  8.5/x. 

2.  Placodium  cerinum.  Thallus  evenly  spreading, 
granular,  sometimes  indistinctly  areolate,  dark-brown. 
Apothecia  small.  Disk  convex,  reddish-brown,  margin 
not  raised.     Spores  typical,  12/x  X  6.5/x. 

3.  Placodium  aurantiacum.  Thallus  varies  from 
evenly  spreading  to  coarsely  granular  and  areolate, 
greenish-yellow  or  lemon  color.  Apothecia  variable 
in  size  and  number.  Disk  flattened  or  slightly  con- 
vex, margin  somewhat  raised,  reddish-brown.  Spores 
typical,  17/u,  X  8/m. 

Jf.  Placodium  citrinum.  Thallus  of  powdery  (so- 
redioid)  granules,  areolate,  lemon  color.  Sterile.  No 
apothecia-bearing  specimens  have  come  to  my  notice. 
The  plant  is  usually  mutualistically  or  antagonistically 
associated  with  species  of  Lecanora^  and  it  may  be  that 
the  spores  of  the  latter  have  been  described  as  the 
spores  of  P.  citrinum. 

5.  Placodium  cinnabarinum.  Thallus  areolate,  are- 
oles  sometimes  scattered,  bright-orange.  Apothecia 
small,  almost  entirely  immersed  in  the  areoles.  Disk 
concave,  margin  slightly  paler  than  thallus.  Spores 
typical,  9/x,  X  4/a. 

6.  Placodium  murorum.  Body  of  thallus  of  convex 
more  or  less  irregular  squamules,  margin  of  elongated 
bifurcate  lobules,  closely  adnate,  orange  color.     Apo- 


GENERA    AND    SPECIES.  137 

thecia  numerous,  small  to  medium.  Disk  flattened  or 
slightly  convex,  darker  orange  than  thallus,  margin 
scarcely  raised.     Spores  typical,  10/x  X  5/x,. 

Placodium  murorum  has  been  classed  by  authors 
with  Lecanora  as  well  as  ParmeUa.  It  occurs  upon 
walls,  rocks,  bricks,  tiles,  mortar,  etc. 

7.  Placodium  elegans.  Thallus  distinctly  foliose, 
radial  growth,  forked  branching,  lobes  of  uniform 
width,  convex  above,  somewhat  concave  below,  ends 
of  branches  turning  down  ;  orange  above,  dark-gray 
beneath  with  black  rhizoids.  Apothecia  medium  to 
large,  cup-shaped.  Disk  orange.  Spores  typical, 
10/x  X  8/x. 

This  species  as  well  as  other  species  of  Placodium 
has  been  classed  with  ParmeUa.  P.  elegans  is  said 
to  occur  on  granitic  rock  on  the  highest  mountains.  It 
has  been  collected  on  Orizaba  at  an  elevation  of  14,850 
feet.  Agassiz  brought  it  from  the  summit  of  the  Jung- 
frau. 

3.   Pyxine. 

Only  two  species  of  this  genus  occur  in  the  United 
States,  one  of  which  is  probably  not  a  Pyxine.  P. 
sorediata  is  nearly  always  sterile.  As  represented  by 
the  only  two  species,  the  thallus  is  foliose,  quite 
large,  thin  and  closely  adnate  to  the  substratum,  branch- 
ing quite  distinct.  Color  of  the  thallus  ash-gray,  re- 
sembling that  of  the  Pkyscias,  to  which  this  group  is 
evidently  closely  related.^ 

The  apothecia  are  discoid.     Disk  dark,  likewise  the 

1  UnlesB  otherwise  stated,  the  algsB  of  any  lichen-genus  or  lichen- 
*pecie»  are  Protococcus  (Cystococcus  humicola  of  Nageli). 


138  GUIDE    TO    THE    STUDY    OF    LICHENS. 

hypothecium,  which  characterizes  the  genus.  The  spores 
are  two-celled,  the  cells  united  by  a  plasmic  thread, 
dark-brown. 

1.  Pyxine  picta.  Thallus  thin,  membranaceous, 
closely  adnate  to  the  substratum,  indistinctly  lobed 
toward  the  margin,  older  portion  of  the  thallus  more 
or  less  warty.  Apothecia  of  medium  size,  discoid,  ses- 
sile. Disk  dark  to  black,  flattened.  Spores  dark- 
brown,  typical  of  the  family,  18/x  X  7/x. 

2.  Pyxine  sorediata.  Thallus  much  branched,  lobed, 
long  and  of  uniform  width,  grayish-green  above,  black, 
with  numerous  rhizoids,  below  ;  numerous  soralia  occur 
along  the  upper  margins  of  the  lobes.  Apothecia  very 
rare.  Disk  flattened  or  convex,  dark.  Spores  dark- 
brown,  typical,  17/x  X  7/x. 

This  lichen  requires  further  careful  study.  It  is 
perhaps  not  a  Pyxine.  Only  scant  and  unsatisfactory 
apothecia-bearing  material  has  come  to  my  notice.  It 
has  been  described  as  Pyxine  cocoes^  Parmelia  sore- 
diata, Pyxine  cocoes  variety  sorediata,  as  a  Physcia, 

etc. 

4.  Physcia, 

The  thallus  is  almost  crustose  in  a  few  of  the  lower 
species  ;  otherwise  it  is  typically  foliose,  much-branched 
and  extending  flatly  over  the  substratum.  The  color 
is  usually  gray  tinged  with  green  above,  with  a  differ- 
ent color  beneath,  usually  lighter,  rarely  dark  to  black, 
much  of  the  dark  coloration  being  due  to  rhizoids.  In 
some  species  the  margin  of  the  thallus-lobes  are  lined 
with  dark  cilia.  Whitish  soralia  are  also  common  upon 
the  thalli  of  many  species. 


GENERA    AND    SPECIES.  139 

The  apotliecin  belong  to  the  tlialline  type,  and  are 
discoid,  sessile,  small  to  medium  in  size.  The  disk  is 
dark  in  color.  There  is  no  yellow  or  orange  colora- 
tion in  this  genus.  It  may  also  be  mentioned  that 
spermagonia  occur  upon  many  species.  The  spores 
are  typical  of  the  family,  closely  resembling  those  of 
Rinodina. 

The  Physcias  have  a  wide  range  ;  the  higher  forms 
are  somewhat  southern.  They  occur  upon  bark  and 
rock. 

Formerly  the  PJiyscias  were  quite  generally  com- 
bined with  Parmelia,  from  which  group  they  are,  how- 
ever, readily  distinguished  by  the  spore-characters  and 
by  the  differences  in  the  appearance  of  the  thallus. 

1.  Physcia  adglutinata.  Thallus  crustose,  thin, 
very  closely  adnate  to  the  substratum,  central  portion 
areolate,  warty,  margin  lobed,  lobes  of  uniform  width  ; 
dark  colored.  Apothecia  small  to  medium.  Disk  dark- 
brown,  margin  slightly  crenulate.  Spores  brown, 
typical,  15/x  X  8.. 5 /a. 

2.  Physcia  obscura.  Thallus  comparatively  small, 
branching,  firmly  attached  to  the  substratum,  green- 
ish-gray above,  black  beneath,  with  numerous  rhizoids. 
Apothecia  small  to  medium,  margin  extending  above 
the  dark-brown  disk.  Spores  brown,  typical,  24/x 
X  10.5/x. 

3.  Physcia  setosa.  Thallus  much  as  in  P.  obscura, 
lobes  broader,  often  bearing  soredia,  black  below,  with 
densely  crowded  black  rhizoids.  Apothecia  rare;  none 
have  come  to  my  notice. 

4.  Physcia  ccesia.     Thallus  comparatively  small  to 


140  GUIDE    TO    THE    STUDY    OF    LICHENS. 

medium,  branching;  lobes  linear,  slender,  pale-gray 
above,  with  darker  soralia,  slightly  darker  beneath, 
with  rigid  rhizoids.     Apothecia  not  seen. 

5.  Physcia  tribacea.  Thallus  rather  small,  minutely 
branched,  lobes  not  uniform  in  size,  crenulate,  greenish- 
gray  above,  light  color  beneath,  rhizoids  few.  Apothe- 
cia small  to  medium,  margin  entire.  Disk  dark-brown 
to  black.     Spores  brown,  oblong,  ovoid,  17/x  X  8/x. 

6.  Physcia  stellaris.  Thallus  rather  small,  branched, 
lobes  of  uniform  width,  lying  flat  upon  the  substratum, 
ash-gray  to  brown  above,  light-brown  beneath,  rhizoids 
comparatively  few.  Apothecia  as  in  P.  tribacea. 
Spores  brown,  typical,  19/x  X  10.0/>t. 

7.  Physcia  pulverulenta.  Thallus  large,  branched, 
lobes  variable  from  linear  to  broad,  brittle,  sometimes 
bearing  minute  conical  or  strap-shaped  outgrowths  ; 
light-gray  to  brown,  overspread  by  a  translucent  white 
coloration.  Apothecia  medium  to  large,  margin  slightly 
elevated  and  bearing  conical  or  warty  outgrowths.  Disk 
dark-brown,  with  a  translucent  white  coloration.  Spores 
dark-brown,  constricted  in  the  middle,  connecting  thread 
not  distinct,  32.5/x  X  17/x. 

8.  Physcia  aquila.  Thallus  large,  much  branched, 
lobes  linear,  gray  to  brown  above,  nearly  the  same 
color  below  with  large  dark  rhizoids,  older  parts  of 
thallus  and  apothecia  bearing  numerous  conical  out- 
growths or  small  thalloid  lobules.  Apothecia  medium, 
margin  often  isidioid.  Disk  dark-brown.  Spores 
large,  brown,  29.0/x  X  18.0/x. 

9.  Physcia  hyjjoleuca.  Thallus  large,  branched,  ad- 
herent to  the  substratum,  ash-gray  above,  pale  beneath, 


GENERA    AND    SPECIES.  141 

rhizoids  sparingly  present  and  black.  Apothecia  nu- 
naerous,  medium  to  large,  cup-shaped,  margin  incurved, 
crenate.  Disk  dark-brown.  Spores  brown,  typical, 
36/x,  X  17/x. 

10.  Physcia  speciosa.  Thallus  branched,  lobes  strap- 
shaped,  bearing  a  few  cilia,  usually  lying  close,  but 
only  loosely  attached  to  the  substratum,  greenish-gray 
above,  lighter  color  beneath  with  comparatively  few 
dark  rhizoids.  Apothecia  medium  to  large,  cup-shaped, 
crenulate  margin  curved  inward.  Spores  brown, 
typical,  21/x  X  Hfi* 

11.  Physcia  comosa.  Thallus  branched  from  two 
to  about  six  times,  lobes  ascending  and  of  quite  uni- 
form width  ;  numerous,  long,  slender,  dark  cilia  from 
the  margin,  rarely  from  the  upper  surface  of  the  thal- 
lus as  well ;  uniform,  pale  ash-gray  above,  paler  below, 
no  rhizoids.  Apothecia  terminal,  margin  extending 
considerably  above  the  gray  disk.  Spores  brown, 
11  fx  X  34/.. 

12.  Physcia  hispida.  Thallus  much  as  in  P.  co- 
mosa but  with  lobes  inflated  at  the  tips,  cilia  usually 
more  slender  and  numerous.  Apothecia  medium,  mar- 
gin only  slightly  raised  above  disk.  Disk  gray  to 
nearly  black.     Spores  brown,  20.5/i,  X  ll/>t- 

13.  Physcia  ciUaris.  Thallus  much  branched,  lobes 
linear,  somewhat  ascending,  branches  terminating  in 
long  slender  cilia,  which  are  usually  darker  than  the 
lobes;  ash-colored  to  dark-brown  above,  nearly  the 
same  color  beneath,  no  rhizoids.  Apothecia  rare,  me- 
dium, cup-shaped,  bearing  some  short  cilia.  Disk 
brown  to  dark.     Spores  dark-brown,  35/x  X  17/a. 


142  GUIDE    TO    THE    STUDY    OF    LICHENS. 

5.   Theloschistes. 

The  thallus  varies  from  almost  foliose  to  fruticose. 
The  fruticose  forms  are  much  branched  and  usually 
bear  long  grayish  cilia  along  the  margin  of  the  lobes. 
Usually  there  is  more  or  less  of  a  yellowish  tinge ;  in 
some  only  a  grayish  color.  Soralia  are  less  common 
than  in  Physcia. 

The  apothecia  are  discoid,  usually  larger  than  in 
Physcia.  Disk  orange,  yellowish,  in  some  species  dark- 
gray  to  nearly  black.  The  spores  resemble  those  of 
Placodium,  from  which  this  group  is  perhaps  pliylo- 
genetically  derived. 

The  Theloschistes  are  more  southern  and  western 
than  the  Physcias.  They  occur  upon  bark,  rock,  old 
walls,  fences,  old  buildings,  etc.  Frequently  they  are 
associated  with  species  of  Physcia. 

1.  Theloschistes  polycarpus.  Thallus  foliose,  lobe 
short,  rounded,  dirty  lemon  to  orange.  Apothecia 
usually  small,  very  numerous,  the  entire  margin  of 
the  thallus  studed  with  them.  Disk  concave,  orange. 
Spores  colorless,  typical,  15^  X  8/a. 

2.  Theloschistes  lychneus.  Thallus  foliose,  branch- 
ing, lobes  broad  and  more  or  less  ascending,  soralia 
often  present;  orange  above,  lighter  color  beneath. 
Apothecia  rare,  medium  size.  Disk  flattened,  red- 
dish-brown.    Spores  colorless,  typical,  12/x  X  8.5/x. 

3.  Theloschistes  concolor.  Thallus  foliose,  minutely 
branching,  lobes  of  uniform  width,  not  ascending, 
greenish-yellow  above,  gray  beneath.  Apothecia  of 
medium  size,  cup-shaped,  margin  somewhat  fibrillose. 
Disk  of  the  same  color  as   thallus.     The  spores  are 


GENERA    AND    SPECIES.  143 

Bmall,  colorless  and  cells  not  distinctly  terminal, 
8.5/x  X  V 

Jf.  T/ieloschistes  parietinus.  Thallus  always  dis- 
tinctly foliose,  but  varial)le  in  the  development  of  the 
lobes  ;  lobes  usually  short  and  rounded  and  somewhat 
upturned  at  the  margin,  pale-lemon  to  reddish-brown. 
Apothecia  from  medium  to  large.  Disk  orange. 
Spores  colorless,  typical,  \2^x  X  7/x. 

This  lichen  has  quite  generally  been  classified  as 
ParmeUa  parietina ;  also  as  Physica  parietina.  An 
older  name,  Candelaria^  was  derived  from  the  fact  that 
the  lichen  was  used  by  the  Swedes  to  give  a  yellow  color 
to  candles  used  in  religious  ceremonies.  In  England  it 
has  been  extensively  used  to  color  Easter  eggs.  This 
is  the  lichen  which  was  recommended  as  a  substitute 
for  quinine  (1815).  It  was  also  highly  recommended  as 
an  astringent  in  hemorrhages  and  as  a  febrifuge.  It 
occurs  in  London  drug-shops  as  "  Common  yellow 
Wall-moss,"  being  probably  chiefly  utilized  by  the 
taxidermist.     It  is  southern  in  its  range. 

5.  Thelosckistes  chrysophthahnus.  Thallus  fruticose, 
branching,  lobes  flat,  terminating  in  rigid  cilia  ;  yel- 
lowish-orange above,  grayish  beneath.  Apothecia 
usually  terminal,  medium  to  large,  margin  usually 
ciliate.  Disk  orange.  Spores  colorless,  typical,  14/oi 
X  7.5;a. 

This  is  a  beautiful  plant,  growing  in  tufts  upon 
trees. 

6.  Tltcloschistes Jiavicans.  Thallus  fruticose,  much 
branched,  pendant,  soralia  often  present,  ciliate  ;  yel- 
lowish-gray to  reddish-brown.     Apothecia  medium  to 


144  GUIDE    TO    THE    STUDY    OF    LICHENS. 

large,  lateral  or  terminal.     Disk  reddish-brown.    Spores 
colorless,  typical,  16/w,  X  7.5/i. 

7.  Theloschistes  leucomela.  Thallus  fruticose,  much 
branched,  lobes  uniform,  flat,  long,  ciliate  ;  gray  above, 
lighter  beneath.  Apothecia  large,  margin  ciliate. 
Disk   dark-gray.     Spores    light-brown,  large,    51/x  X 

This  is  a  southern  species  and  a  very  handsome 
plant.  Fine  specimens  from  Lower  California  have 
come  to  my  notice.  It  would  have  been  perhaps  more 
correct  to  classify  this  lichen  with  Physcia,  in  accord- 
ance with  Lindsay  and  others. 

VI.    PARMELIACEyE.^ 

In  this  family  the  thallus  varies  from  typically 
crustose  to  typically  foliose  and  fruticose.  In  all 
forms  above  the  crustose  types  the  thallus  is  much 
branched.  The  apothecia  belong  to  the  thalline  type ; 
they  are  discoid,  and  attain  their  maximum  size  in 
such  genera  as  Usnea,  Parmelia  and  Peltigera. 

The  position  and  limitation  of  the  family  are  depend- 
ent upon  the  following  characters:  1.  The  absence 
of  stipes  and  podetia  excludes  it  from  the  Caliciacece 
and  CladoniacecE.  2.  The  presence  of  the  thalline 
apothecia  excludes  it  from  the  Lecidiacece.  3.  The  non- 
union of  the  spore-cells  excludes  it  from  the  Physciacece. 
4.  Presence  of  discoid  sessile  apothecia  separates  it 
from  the    Graphidacece  and    Verrucariaceoe.     5.  The 

1  In  the  study  of  most  of  the  genera  of  this  family  I  received  speci- 
mens from  the  collection  of  my  friend  W.  W.  Calkins,  for  the  use  of 
which  I  express  my  sincere  gratitude. 


GENERA    AND    SPECIES.  145 

absence    of   blue-green    algje    ( CyanophycecB)    finally 
separates  it  from  the  Collemacece  and  Pannariacece. 

KEY  TO   THE   GENERA. 

Thallus  crustose  and  areolate  to  thickly 
warty  and  minutely  foliosc. 
Spores  not  simple. 

Multilocular,  dark 1.   Urceolaria. 

Five  to  seven-celled,  acicular,  color- 
less   2,  Hiematomma. 

Spores  simple,  colorless. 

Usual  size  and  number  (8)    ....     5.  Lecanora. 
Very  minute  and  numerous  (200)      .     4-  Acarospora. 
Thallus  foliose,  lobed  or  branching,  spores  colorless. 

Spores  two-celled <5.  Speerschneidera. 

Spores  simple. 

Thallus  greenish,  lobes  never  erect  .     6.  Pannelia. 
Thallus   brownish,  lobes  sometimes 

erect 7.   Cetraria. 

Thallus  fruticose. 

Lobes  distinctly  flattened,  spores  colorless. 

Spores  two-celled 8.  Ramalina. 

Spores  simple 9.  Rocella. 

Lobes  not  distinctly  flattened,  yellow- 
ish     10.  Evernia. 

Lobes    cylindrical,    filamentous    and 
very  long,  spores  simple. 
Central  hyp  ha  I  core  wanting. 

Thick  exosporium 11-  Alectoria. 

Normal  exosporium 12.  Bryopogon. 

Central  hyphal  cores  present   .     .     .13.   Usnea. 

1.    Urceolaria. 

Thallus  crustose,  usually  quite  thick  and  areolate, 
the  areoles  becoming  distinctly  convex  or  warty  in 
some  species.  Tlie  prevailing  color  of  the  upper  sur- 
face is  gray,  lower  surface  whitish.  The  algaj  are 
no  doubt  Protococcus ;  they  usually  occur  in  groups 
of  six  to  twelve,  tlius  differing  from  the  usual  forms 
which  occur  singly. 


146  GUIDE    TO    THE    STUDY    OF    LICHENS. 

The  apothecia  are  quite  small,  globose,  and  are 
immersed  in  the  thallus,  opening  by  a  pore.  The 
hypothecium  is  usually  dark.  The  genus  should 
perhaps  be  placed  with  the  VerriicariacecE,  since 
its  apothecial  characters  point  toward  such  a  relation- 
ship. 

The  spores,  when  mature,  are  multilocular  and 
dark.  The  immature  spores  are  simple,  colorless,  and 
larger  than  the  mature  spores.  It  should  also  be 
borne  in  mind  that  the  mature  spores  are  often  quite 
structureless. 

Most  of  the  species  are  northern  in  their  range. 
They  occur  upon  rocks,  a  few  upon  the  soil. 

1.  Urceolaria  actinostoma.  Thallus  comparatively 
thin,  areola te,  areoles  never  convex  ;  gray  to  dark-gray. 
Apothecia  small,  immersed  in  somewhat  convex  areoles. 
Disk  dark.     Spores  dark,  multilocular,  14)u,  X  7.5/x. 

2.  Urceolaria  scruposa.  Thallus  quite  thick,  areo- 
late,  fissured,  gray.  Apothecia  immersed  in  somewhat 
elevated  areoles.  Disk  somewhat  darker  than  thallus. 
Spores  dark-brown,  elliptical,  multilocular,  21/jt  X  9/a. 

An  orange  coloring  substance  is  obtained  from  the 
Urceolarias ;  it  was  used  in  dyeing  woollen  goods. 

2.  Hcematomma. 

This  genus  is  usually  combined  with  Lecanora, 
though  its  spore-characters  are  wholly  different.  The 
thallus  is  crustose  but  very  thick;  sometimes  covered 
over  by  a  soredial  powder.  The  color  is  gray  tinged 
with  green,  or  sometimes  yellowish. 

The  apothecia  vary  from  medium  to  quite   large; 


GENERA    AND    SPECIES.  147 

they  are  usually  discoid,  irregular  in  outline,  sessile  or 
adnate  upon  the  thallus.  The  disk  is  usually  flattened, 
margin  only  slightly  elevated.  Hypothecium  is  color- 
less. 

The  spores  are  long,  acicular,  pointed  toward  one 
end,  curved,  undulate  or  twisted,  colorless,  five  to 
seven-celled.  The  spores  are  very  characteristic,  and 
when  once  seen  are  not  likely  to  be  mistaken  ;  they  re- 
semble most  nearly  those  of  Bacidia. 

I'he  species  occur  upon  rock,  trees,  earth,  logs,  etc. 
They  are  somewhat  northern  in  their  range  and  prefer 
mountainous  districts. 

1.  HcBmatomma  punicea.  Thallus  areolate  to  warty, 
greenish-gray.  Apotliecia  small.  Disk  bright  reddish- 
brown.     Spores  acicular,  colorless,  five'to  seven-celled, 

2.  Hcematomma  ochrophcea.  Thallus  thick,  warty, 
not  fissured,  grayish-green,  white  internally.  Apothecia 
small  to  medium.  Disk  pale  to  dark  brown.  Spores 
colorless,  indistinctly  five  to  seven-celled,  curved, 
49/x  X  4.5/x. 

S.  Hcematomma  ventosa.  Thallus  very  thick,  deeply 
fissured;  surface  areolate,  warty;  yellowish-green  to 
dirty  green  above,  white  within  and  beneath.  Apothecia 
medium  to  large,  spreading,  margin  irregular  in  out- 
line and  somewhat  lobulate.  Disk  reddish-brown. 
Spores  five  to  seven-celled,  colorless,  curved,  thinner 
toward  one  end,  37/x  X  2/x.. 

The  so-called  L^'Cidea  parasitica  (perhaps  a  fungus) 
is  often  parasitic  upon  this  plant.  H.  ventosa  is  closely 
related  to  the  foreign  Lecanora  esculenta  already  men- 


148  GUIDE    TO    THE    STUDY    OF    LICHENS. 

tioned  in  the  historical   review.     The    HcBmatommas 
have  also  found  a  place  in  the  dyeing  industries. 

3.  Lecanora. 

The  thallus  varies  from  crustose  to  somewhat  foliose. 
It  is  highly  probable  that  the  Parmelias  are  the 
direct  descendants  of  the  Lecanoras.  The  amateur  is 
likely  to  confuse  the  Lecanoras  and  Biatoras^  since 
they  resemble  each  other  in  their  general  characters, 
especially  the  spore-characters.  The  foliose  forms 
have  numerous  small,  more  or  less  jjlicate,  lobes  which 
are  somewhat  ascending  and  bear  numerous  rhizoids. 
Color  of  the  thallus  varies  from  light-green  to  dark. 

The  apothecia  are  generally  plentiful;  as  compared 
with  the  apothecia  of  the  Biatoras  they  are  quite  large. 
They  are  discoid,  sessile,  not  immersed ;  margin  ex- 
tending somewhat  above  the  brown  to  nearly  black 
disk.     Hypothecium  colorless. 

The  spores  are  simple,  colorless,  elliptical,  some- 
what variable  in  size  and  form. 

The  Lecanoras  occur  upon  bark  and  rock  and  have 
a  wide  range. 

1.  Lecanora  lacustris.  Thallus  very  thin,  uniformly 
spreading,  indistinctly  areolate  ;  reddish-brown.  Apo- 
thecia small,  scattering,  partially  immersed,  margin 
somewhat  raised.  Disk  reddish-brown  to  dark.  Spores 
rarely  mature. 

2.  Lecanora  orosthea.  Thallus  thin,  powdery  to 
finely  granular,  pale  sulphur  color.  Apothecia  of 
medium  size,  margin  barely  raised,  somewhat  crenate. 
Disk  pale-brown.     Spores  ovoid,  colorless,  14/*  X  7.5/i. 


•LATK  L/.  Cnistosc  Tyiu's.  Vn 
Y.  (Mark  in  ilic  li.Tl.iiriimi  of  tlic 
Science,     Lccduora  jKillida. 


ifon 


nllf.'tinli    nf    X . 

ia  Ai'adeiiiN   nf 


GENERA   AND    SPECIES.  149 

S.  Lecanora  Bockii.  Thallus  granular,  somewhat 
areolate  ;  dark.  Apothecia  small,  slightly  raised  above 
thalhis.  Disk  somewhat  lighter  in  color  than  thallus. 
Spores  rare,  typical. 

4.  Lecanora  calcarea.  Thallus  areolate,  dark. 
Apothecia  small,  usually  numerous,  irregular,  margin 
slightly  raised  above  the  brown  to  dark-brown  disk. 
Spores  elongated,  slightly  curved,  15.5^  X  4/x,. 

5.  Lecanora  Hageni.  Thallus  granular  to  indis- 
tinctly warty,  gray  to  dark.  Apothecia  small,  numer- 
ous ;  margin  entire,  elevated  ;  light-gray.  Disk  reddish- 
brown  to  dark-brown.  Spores  ovoid  or  elliptical,  7.5/x 
X  4.5/x. 

Nos.  4  and  5  are  generally  associated  with  species 
of  Placodium. 

6.  Lecanora  pallida.  Thallus  uniform,  areolate, 
rarely  granular  and  warty,  pale  color.  Apothecia 
medium  to  large,  somewhat  lobulate  or  folded,  elevated 
margin.  Disk  flattened,  pale-brown  to  brown.  Spores 
typical,  12/i,  X  6/u,. 

7.  Lecanora  Cupressi.  Thallus  granular  to  warty, 
pale-green.  Apothecia  small  to  medium,  numerous, 
margin  crenulate.  Disk  pale  yellowish-brown.  Spores 
typical,  slightly  curved,  13/w,  X  4.5/x. 

8.  Lecanora  varia.  Thallus  much  as  in  L. 
Cupressi,  more  distinctly  warty.  Apothecia  as  in 
No.  7,  margin  more  elevated  ;  spores  the  same. 

Nos.  7  and  8  are  evidently  closely  related,  if  not 
identical.  L.  varia  is  quite  common  and  has  a  wide 
range.  Saussure  and  Agassiz  collected  specimens  on 
the  summits  of  the  Alps. 


150  GUIDE    TO    THE    STUDY   OF    LICHENS. 

9.  Lecanora  suhfusca.  Thallus  rudimentary  to 
warty  or  areolate,  light-gray  to  light-brown.  Apo- 
thecia  small  to  medium,  margin  entire  and  some- 
what flexed,  slightly  elevated.  Disk  flattened  to 
convex,  reddish-brown  to  black.  Spores  typical, 
9/x  X  6/t. 

It  is  perhaps  likely  that  most  authors  combine  several 
species  in  the  above.  It  is  of  common  occurrence  and 
has  a  wide  range. 

10.  Lecanora  atra.  Thallus  evenly  spreading,  be- 
coming warty  and  areolate,  gray.  Apothecia  medium, 
margin  slightly  raised  above  the  flattened  black  disk. 
Spores  typical,  12/x  X  6/x. 

This  lichen  has  been  used  in  dyeing. 

11.  Lecanora  pallescens.  Thallus  rather  thin, 
more  or  less  ridged  or  chinky,  according  to  the 
nature  of  the  substratum  (bark),  surface  smooth ; 
pale-gray.  Apothecia  medium  to  large,  margin  some- 
what rugose.  Disk  pale-brown.  Spores  large,  typical, 
SQfi,  X  21/*. 

"  This  lichen  yielded  the  *  Orseille  d'Auvergne.' 
The  pigment  was  prepared  chiefly  at  St.  Flour  and 
Limoges,  and  the  lichen  was  collected  by  the  peasantry 
of  Auvergne,  Limousin,  Languedoc,  Provence,  Lyons 
and  other  districts  of  southern  France.  Manufacturers 
distinguished  two  varieties,  white  and  gray,  depend- 
ing chiefly  on  the  maturity  and  purity  of  the  plant, 
the  latter  being  preferred.  Under  the  name  of  '  Light 
Crottle  '  it  has  been  much  used  by  the  Scotch  High- 
landers to  yield  an  orange  or  reddish  dye  for  woollen 
goods  ;  and  as  the  common   '  Crab's-eye   Lichen  *  it 


GEJfKRA    AND    SPECIES.  151 

appears  to  have  been  gathered  in  the  North  of  Eng- 
land." —  Lindsay. 

12.  Lecanora  cenisia.  Thallus  thick  and  readily 
removed  from  substratum  (rock),  consisting  of  large 
confluent  warts,  light-gray.  Apothecia  medium  to 
large,  attached  by  a  narrow  neck ;  crenate,  mar- 
gin elevated  above  the  dark  disk.  Spores  typical, 
12/.  X  8/01. 

13.  Lecanora  muralis.  Thallus  lobed  at  the  mar- 
gin, areolate  toward  the  interior,  sometimes  of  scat- 
tered entire  lobes.  Apothecia  small.  Disk  somo.what 
convex,  brown.     Spores  typical,  10.5/a  X  5/x. 

IJf..  Lecanora  tartar ea.  Thallus  thick,  of  imbricate 
ascending  branches,  sometimes  becoming  semi-foliose 
or  semi-fruticose,  light-gray  to  grayish-green.  Apo- 
thecia medium  to  large,  margin  somewhat  rugose. 
Disk  brown  to  reddish-brown.  Spores  large,  typical, 
52/>i  X  21/a. 

This  lichen  was  employed  to  make  litmus  and  to 
produce  a  purple  for  dyeing  woollen  goods  and  nowhere, 
perhaps,  used  more  extensively  than  in  England.  The 
lichen  was  sold  at  about  eighty  cents  per  stone  of 
twenty-two  pounds.  The  same  rocks  were  scraped 
once  every  five  years. 

15.  Lecanora  ruhina.  Thallus-lobes  ascending  show- 
ing a  fruticose  tendency,  grayish-green  above  and 
toward  the  apex,  brown  and  dark  below  and  toward 
the  basq.  Apothecia  medium  to  large  ;  margin  cre- 
nate and  raised  somewhat  above  the  pale  yellowish- 
brown  disk.     Spores  tyj^ical,  7.5/a  X  -i.O/x. 


152  GUIDE   TO    THE    STUDY    OF   LtCHENS. 

Jf..  Acarospora. 

This  genus  is  by  some  authors  placed  with  Lecanora. 
The  thallus  is  crustose  and  rudimentary  in  the  lower 
forms ;  in  the  higher  forms  it  becomes  foliose  and 
lobed,  especially  toward  the  margin.  In  many  re- 
spects the  thallus  resembles  that  of  Hcematomma. 
Color  dark  in  the  lower  forms  and  yellowish  in  some 
of  the  higher  forms.  Algas  are  Pleurococcus  vulgaris 
as  in  Endocarpon. 

The  apothecia  are  immersed  in  the  thallus,  variable 
in  size  and  form.  The  disk  varies  from  orbicular  to 
irregularly  lobate  or.  crenate  ;  it  is  usually  flattened, 
more  rarely  convex,  or  margin  slightly  elevated. 
Color  of  disk  varies  from  dark  to  yellowish.  The 
spore-sacs  are  cylindrical,  and  each  one  contains  sev- 
eral hundred  very  minute  simple  colorless  spores 
which  are  held  together  by  a  gelatinous  substance, 
so  that  the  entire  contents  may  be  ejected  or  forced 
out. 

The  Acarospora  are  quite  widely  distributed  and 
occur  principally  upon  rock  (granite)  and  sandy  soil. 

1.  Acarospora  privigna.  Thallus  rudimentary,  yel- 
lowish to  dark.  Apothecia  small,  orbicular,  scattered ; 
margin  slightly  elevated  above  the  dark  flat  disk. 
Spores  elliptical,  typical,  3/a  X  l-^i^- 

2.  Acarospora  cervina.  Thallus  areola te,  dark  to 
nearly  black.  Apothecia  barely  raised  above  the 
thallus,  often  remaining  after  the  thallus  is  worn 
away,  irregular  in  outline.  Disk  dark.  Spores 
closely  adherent  owing  to  a  gelatinous  substance, 
typical. 


GENERA    AND    SPECIES.  153 

This  plant  is  often  found  associated  with  species  of 
Placodium. 

3.  Acarospora  dealbata.  Thalhis  of  white  scattered 
warts  of  considerable  .thickness.  Apothecia  immersed, 
one  in  each  areole.     Disk  black.     Spores  typical. 

5.    Speer  Schneider  a. 

This  genus,  as  represented  by  the  single  species,  is 
closely  related  to  Parmelia.  The  thallus  is  foliose,  much 
branched,  with  lobes  of  uniform  width.  There  is  also 
a  slight  fruticose  tendency.  The  apothecia  are  rather 
small,  sessile  upon  the  upper  surface  of  the  thallus. 
Disk  light-brown.  The  spores  are  small,  colorless, 
elliptical  and  distinctly  two-celled. 

1.  Speerschneidera  euploca.  Thallus  much  branched, 
lobes  slender,  of  uniform  width  and  somewhat  ascend- 
ing, gray.  Apothecia  cup-shaped,  sessile.  Disk  light- 
brown.     Spores  typical. 

This  is  the  only  species  reported  from  the  United 
States,  it  is  southern  in  its  range.  The  specimens 
which  came  to  my  notice  were  associated  with  species 
of  Collema.  It  is  a  small  plant,  but  has  a  very  char- 
acteristic appearance. 

6.  Parmelia. 

It  is  highly  probable  that  this  genus  is  phylogeneti- 
cally  derived  from  Lecanora^  as  seems  evident  from  a 
comparison  of  the  higher  Lecanoras  and  the  lower 
ParmeJias.  The  exact  relationship  of  the  Hcematom- 
mas,  Acarosporas  and  Sj^eerschneidera  is  not  known. 

The  thallus  of  the  Parmelias  is  foliose,  large,  dis- 
tinctly branched  and  lobed.     It  is  held  to  tlie  substra- 


154  GUIDE    TO   THE    STUDY    OF   LICHENS. 

turn  by  black  rhizoids.  White  or  light  colored  soralia 
occur  in  a  number  of  the  species.  As  compared  with 
the  Physcias  the  thallus  is  larger  and  less  distinctly 
ash-gray,  The  color  varies  from  gray  and  brown 
tinged  with  green  and  bluish-green  to  brown  and  dark. 

The  apothecia  are  distinctly  cup-shaped  and  vary 
from  medium  to  very  large.  It  shows  perhaps  the 
highest  development  of  the  thalline  type.  It  is  in 
reality  a  secondary  thallus  having  a  combined  radial 
and  centric  structure.     The  disk  is  generally  brown. 

The  spores  are  simple,  colorless,  elliptical,  often 
bearing  oil-globules  ;  the  spore-wall  is  thin. 

The  Parmelias  are  common  everywhere,  occurring 
upon  trees,  rocks,  stone  walls,  fences,  roofs  of  old 
buildings,  etc.  Some  acquire  considerable  dimensions, 
reaching  three  or  four  feet  in  diameter.  In  many  cases 
there  is  continued  marginal  growth  while  the  central 
portion  dies  away,  thus  producing  a  semblance  to  the 
"fairy  rings"  of  toad-stools. 

1.  Parmelia  conspersa.  Thallus  quite  large,  growth 
radial,  branched  with  lobes  imbricate  (overlapping)  ; 
upper  surface  usually  smooth,  sometimes  bearing  warty 
outgrowths,  soralia  rare,  brownish  to  greenish  ;  lower 
surface  brown  with  numerous  rhizoids.  Apothecia 
small  to  medium,  margin  entire.  Disk  olive-brown. 
Spores  typical,  13/x  X  Siw- 

2.  Parmelia  multisporum  n.  sp.  Thallus  of  medium 
size,  lobed,  adnate  to  substratum  ;  upper  surface  smooth 
and  olive  color.  Apothecia  numerous.  Disk  olive  to 
chestnut-brown;  thecae  bearing  from  50  to  100  color- 
less elliptical  spores,  5/x,  X  4/a. 


GENERA    AND    SPFX'IF.S.  155 

This  species  may  be  identical  with  P.  tceniata^  though 
it  differs  somewhat  in  the  characteis  of  the  thallus. 
In  the  latter  the  spores  are  also  more  numerous  (100 
or  more)  and  smaller  (2.5/x  X  !/-«■)•  So  far  as  could 
be  determined  P.  multisporuin  is  a  western  species,  oc- 
curring in  Washington,  Idaho  and  Utah.  The  mate- 
rial which  came  to  notice  was  labelled  P.  olivacea, 
which  has  the  same  general  characters  but  bears  only 
the  usual  number  of  spores  in  each  spore-sac  (8). 

3.  Parmelia  caperata.  Thallus  from  medium  to 
large,  of  typical  radial  growth,  branching,  lobes 
rounded,  more  or  less  crenulate,  and  margins  turned 
slightly  upward  ;  upper  surface  rugosely  folded,  bluish- 
green,  soralia  upon  the  ridges  of  the  folds ;  lower 
surface  black,  brown  near  margin.  Apothecia  few 
or  wanting,  medium  size,  margin  often  covered 
with  soralia.  Disk  chestnut-brown.  Spores  typical, 
25/x  X  12/x,. 

In  the  north  of  Ireland  and  on  the  Isle  of  Man  this 
lichen  is  known  as  "  Stone  Crottles,"  and  was  exten- 
sively used  by  the  peasantry  for  dyeing  woollen  fabrics 
a  lemon  color.  The  lichen  has  a  wide  range,  occur- 
ring throughout  the  United  States,  South  America, 
Europe  and  other  countries. 

^.  Parmelia  physodes.  Thallus  medium  to  large, 
much  branched,  lobes  linear  and  somewhat  ascending ; 
tips  inflated,  upper  surface  generally  bearing  numerous 
spermagonia,  soralia  sometimes  present,  brownish  to 
ash-gray  ;  lower  surface  black,  brownish  towanl  tips. 
Apothecia  usually  present.  Disk  chest  nut-brown. 
Spores  small,  typical,  G/x  X  4.5/x. 


156  GUIDE    TO    THE    STUDY    OF    LICHENS. 

This  species  is  the  "  dark  crottle "  of  the  Scottish 
peasantry  by  whom  it  was  used  to  dye  woollen  stuffs 
brown.  It  was  also  used  as  an  article  of  diet  and  in 
the  manufacture  of  a  gum  similar  to  gum-ar?bic. 

5.  Parmelia  saxatilis.  Thallus  medium  to  large, 
lobes  narrowed,  terminal  ones  small ;  upper  surface 
smooth,  reticulately  rugose,  sometimes  brownish,  warty 
(isidioid)  outgrowths  covering  entire  thallus,  greenish- 
gray  ;  lower  surface  black,  with  numerous  black  rhiz- 
oids.  Apothecia  medium,  sometimes  wanting.  Disk 
brown.     Spores  typical,  11/x.  X  9/x. 

This  is  the  "Steu-laf"  of  Sweden  and  Norway, 
where  it  was  used  to  dye  thread,  yarn,  etc.,  a  brown  or 
reddish-brown  color.  In  Scotland  it  is  one  of  the 
most  common  "  crottles  "  and  is  also  known  as  "  Stane- 
raw  "  or  "  Staney-rag."  Not  only  do  the  peasantry 
use  it  but  it  would  appear  upon  the  evidence  of  the 
border  ballads  that  the  border  fairies  were  dressed  in 
tunics  dyed  with  this  lichen. 

"  Like  the  feld-elfin  of  the  Saxons,  the  usual  dress 
of  the  fairies  is  green ;  though  on  the  moors  they  have 
been  sometimes  observed  in  heath-brown,  or  in  weeds 
dyed  with  '  Stane-raw '  or  '  lichen.'  This  lichen  was 
also  used  in  medicine  as  an  astringent;  by  the  ancients 
it  appears  to  have  enjoyed  a  celebrity  as  a  sovereign 
remedy  for  epilepsy  and  the  plague."  —  Lindsay. 

6.  Parmelia  Borreri.  Thallus  large,  lobes  rounded, 
with  crenulate  margin,  bearing  a  few  black  cilia  ;  upper 
surface  bearing  numerous  warty  (isidioid)  outgrowths, 
bluish-green  color,  no  soralia ;  lower  surface  light- 
brown    to   whitish   with    black    rhizoids.     Apothecia 


I'LA'l'K  III.  Foliosc  Typrs,  tliallus  divitltMl.  F1..111  Mt. 
'rmiKilpais.  I,  I'tiniu'lid  iterlata.  '2.  /'annelid  jifii/sodes. 
While  the  latter  is  classed  as  luliose,  il  shows  a  decided 
fniticose  teiideiiey. 


GENERA    AND    SPECIES.  157 

few   or    none.     Disk    brown.     Spores    few,    typical, 
11/x  X  8.5/x. 

7.  Parmelia perforata.  Thallus  large,  lobes  large, 
rounded,  margin  somewhat  crenulate,  few  or  no  soralia, 
grayish-green,  spermagonia  usually  numerous  ;  lower 
surface  black,  with  long  black  rhizoids.  Apothecia 
large,  bottom  of  cup  perforate.  Disk  brown.  Spores 
typical,  17/x  X  10/a, 

8.  Parmelia  latissima.  Thallus  large,  rounded  lobes, 
with  crenate  margin,  and  bearing  white  soralia,  light- 
green  or  grayish-green  above ;  lower  surface  black, 
becoming  brown  toward  margin.  Apothecia  rare  or 
wanting.     Disk  brown.     Spores  typical,  23.5/x  X  9.5/x. 

This  is  evidently  a  tropical  lichen.  It  is  often  con- 
fused with  the  following  species. 

9.  Parmelia  perlata.  Thallus  large,  lobes  rounded, 
crenate,  bearing  white  soralia,  grayish-green ;  lower 
surface  as  in  P.  latissima.  Apothecia  usually  want- 
ing.    Spores  typical,  13/x  X  9.0/x. 

This  lichen  yields  a  fine  orchill.  It  was  at  one 
time  imported  into  England  from  the  Canary  Islands 
as  "Canary  rock-moss." 

7.    Cetraria. 

This  genus  is  perhaps  phylogenetically  derived  from 
some  Parmelioid  type  or  types.  The  thallus  varies 
from  foliose  to  typically  fruticose,  but  in  all  cases  the 
lobes  are  flattened  and  broad.  The  amateur  will  no 
doubt  confound  some  species  with  Parmelia.  In 
general,  however,  the  thallus  is  more  brittle  and  dif- 
ferent  in    color ;    brown    predominating.       In    some 


158  GUIDE    TO    THE    STUDY    OF    LICHENS. 

species  there  is  a  yellow  coloration.  Cilia  are  fre- 
quently present;  soralia  are  comparatively  rare. 

The  apothecia  are  of  medium  size,  discoid,  usually 
less  markedly  cup-shaped  than  in  Parmelia.  Disk 
chestnut-brown,  shining,  margin  somewhat  crenate 
or  torn.  The  spores  are  simple,  elliptical  and  color- 
less, somewhat  smaller  than  in  Parmelia, 

Most  of  the  Cetrarias  are  northern,  occurring  upon 
trees  and  rocks. 

1.  Cetraria  Fahlunensis.  Thallus  foliose,  much 
branched,  smooth,  somewhat  ascending,  marginal  lobes 
olive-brown  to  nearly  black  above ;  dark  beneath 
with  numerous  rhizoids.  Apothecia  few,  medium  to 
large,  thin.  Disk  chestnut-brown,  smooth.  Spores 
typical,  8/x  X  6.5/x. 

This  lichen  furnishes  a  red  (vermilion)  dye. 

2.  Cetraria  ciliaris.  Thallus  foliose  and  much 
branched,  lobes  somewhat  ascending  and  cilia te, 
smooth ;  ash-gray  tinged  with  bluish-green  above, 
light-brown  beneath,  rhizoids  few.  Apothecia  medium 
to  large,  margin  crenulate  or  torn.  Disk  chestnut- 
brown,  smooth.     Spores  typical,  spherical,  6/x. 

3.  Cetraria  juniperina.  Thallus  foliose,  medium 
size,  branched,  terminal  lobes  ascending,  lacerate ; 
straw  color  on  both  surfaces.  Apothecia  of  medium 
size,  margin  crenate.  Disk  chestnut-brown.  Spores 
typical,  S/x  X  6.5/x. 

Upon  boiling  in  water  this  lichen  yields  a  yellow 
coloring-matter  which  was  much  used  in  Sweden  for 
dyeing  home-made  cloth  fabrics  and  Easter  eggs.  With 
Placodium  murorum  it  was  at  one   time  highly  rec- 


GENERA    AND    SPECIES.  159 

ommended  for  the  cure  of  jaundice  (according  to  the 
similia  similihus  curantur   principle  of  homeopaths). 

4.  Cetraria  lacunosa.  Thallus  foliose,  rather  large, 
upper  surface  reticulate,  bluish-green  tinged  with 
gray ;  lower  surface  brownish.  Apothecia  medium. 
Disk  chestnut-brown,  base  sometimes  perforate,  as  in 
Parmelia  perforata.     Spores  typical,  7.5;u,  X  5./);tx. 

Tiiis  species  is  often  confounded  with  C.  ciliaris. 

5.  Cetraria  cucullata.  Thallus  fruticose,  terminal 
lobes  rather  finely  divided  ;  straw  color,  darker  toward 
base.  Apothecia  large,  attached  to  che  lower  surface 
of  turned  terminal  lobes.  Disk  chestnut-brown.  Spores 
typical,  9.5/x  X  5.5/x. 

6.  Cetraria  Islandica.  Thallus  fruticose,  lobes 
comparatively  narrow,  rolled,  rigid,  erect;  margin 
lined  with  rigid  cilia ;  upper  surface  chestnut-brown, 
lower  surface  somewhat  lighter.  Apothecia  medium. 
Disk  chestnut-brown.     Spores  typical. 

This  lichen,  commonly  known  as  "  Iceland  moss," 
has  enjoyed  great  popularity  as  a  medicinal  substance 
and  as  an  article  of  diet.  It  is  still  extensively  used  as 
food  for  convalescents  and  those  having  weak  stomachs. 
Icelanders  powder  it  and  use  it  as  flour.  In  Scandi- 
navia it  is  used  as  fodder  for  cattle.  It  yields  a 
brown  color  which  was  once  much  used  for  dyeing 
woollen  goods. 

According  to  the  United  States  Dispensatory,  Ice- 
land moss  is  demulcent,  nutritious  and  tonic,  well  cal- 
culated for  affections  of  the  mucous  membranes  of  the 
lungs  and  bowels  in  which  the  local  disease  is  asso- 
ciated with   debility  of   the  digestive  organs,  or   the 


160  GUIDE    TO    THE    STUDY    OF    LICHENS. 

general  system.  The  plant  has,  however,  no  active 
curative  property,  and  is  fast  going  into  disuse  as  a 
medicine. 

8.  Ramalina. 

In  this  genus  the  thallus  is  typically  fruticose,  the 
lobes  being  flattened.  In  the  majority  of  species  the 
surface  is  smooth.  The  length  of  the  thallus  varies 
greatly ;  in  the  smallest  species  an  inch  or  less  to 
several  feet  in  the  largest.  The  branches  are  strap- 
shaped,  and  in  a  few  species  tend  to  become  cylin- 
drical. Color  varies  from  greenish  to  gray  or  even 
brown.     Large  soralia  occur  on  some  species. 

The  apothecia  vary  from  rather  small  to  medium  in 
size.  They  are  flattened  or  cup-shaped,  lateral,  occur- 
ring either  along  the  margin  or  upon  the  flat  surface. 
Disk  pale  brown.  Spores  are  colorless,  elliptical,  two- 
celled. 

The  Ramalinas  occur  upon  trees  and  rocks  ;  they 
are  not  plentiful. 

i.  Ramalina  minuscula.  Thallus  minute,  half  an 
inch  or  less  in  height,  branches  canaliculate ;  ter- 
minal branches  very  short ;  soralia  sometimes  present ; 
color  light-gray.     Apothecia  and  spores  not  seen. 

2.  RarnaUna  calicaris.  Thallus  one  or  two  inches 
in  height ;  lobes  comparatively  thin  and  broad,  some- 
what canaliculate  aud  slightly  reticulate,  green.  Apo- 
thecia of  medium  size,  terminal  tendency,  somewhat 
cup-shaped.  Disk  light-brown.  Spores  typical,  not 
curved,  10.5/x,  X  5.5/a. 

Most  authors  recognize  a  number  of  varieties,  some 
of  which  no  doubt  deserve   the   rank  of  species.     R, 


Oenera  and  species.  161 

caUcaris  has  a  wide  range  and  usually  occurs  upon 
trees  (oak  in  particular)  ;  it  is  also  said  to  occur  upon 
rock.  The  species  has  been  made  use  of  as  a  gum  in 
calico-printing,  in  the  preparation  of  "parchment" 
andpasteboard,  and  in  the  manufacture  of  hair-pow- 
ders. The  soralia-bearing  specimens  (mealy  Ramalina 
calicaris)  have  been  highly  recommended  as  an  arti- 
cle of  diet.  It  has  also  found  a  use  in  the  treatment 
of  chilblains  and  chapped  hands.  A  variety  obtained 
from  Teneriife  yields  a  yellow  dye.  According  to 
another  authority  the  species  yields  a  rich  red  dye 
equal  to  that  obtained  from  Rocella  tinctoria  which 
was  used  in  dyeing  silken  and  woollen  goods.  The 
plant  was  said  to  have  brought  $5,000  per  ton  in 
England. 

3.  Ramalina  homalea.  Thallus  large,  rather  spar- 
ingly branched,  lobes  ribbon-like,  thick,  rigid,  smooth, 
not  canaliculate  ;  gray  to  brown.  Apothecia  medium, 
with  a  terminal  tendency,  sometimes  distinctly  cup- 
shaped.  Disk  about  the  same  color  as  the  thallus. 
Spores  typical,  somewhat  curved,  loya  X  5/x. 

This  lichen  is  essentially  southern,  and  occurs  upon 
rocks.     It  is  no  doubt  rich  in  coloring  properties. 

^.  Ramaliud  cenichis.  Thallus  rather  small,  spar- 
ingly branched,  lobes  somewhat  flattened  to  nearly 
cylindrical,  gray  ;  smooth,  becoming  dark  spotted. 
Apothecia  medium,  cup-shaped.  Disk  about  the  same 
color  as  thallus.     Spores  typical,  not  curved,  15/x  X  -^f^' 

5.  Ramalina  polymorpha.  Thallus  long,  much 
branched  ;  lobes  narrow,  flattened,  bearing  large 
soralia.     Apothecia  rare.     Spores,  14/x  X  ^Z^*- 


162  GUIDE    TO    THE    STUDY    OF    LICHENS. 

6.  JRamalina  rigida.  Thallus  long  and  much 
branched  ;  lobes  very  slender,  flattened,  gray.  Apo- 
thecia  rather  small,  lateral,  not  cup-shaped.  Disk 
somewhat  convex,  color  of  thallus.  Spores  typical, 
oblong,  not  curved,  21/x  X  4/x. 

7.  Bamalina  reticulata.  Thallus  very  long  (sev- 
eral feet),  pendulous,  much  branched  ;  lobes  slender, 
flattened,  reticulately  perforate.  Apothecia  lateral, 
small.  Disk  convex  and  of  the  same  color  as  the 
thallus.     Spores  typical,  curved,  14/x  X  7/x. 

This  lichen  is  at  once  recognized  by  the  reticulate 
perforations  of  some  of  the  lobes,  or  perhaps  more  cor- 
rectly the  reticulate  branching  of  certain  portions.  It 
is  southern  and  occurs  upon  trees. 

9.  Rocella. 

This  is  a  typically  fruticose  genus.  The  thallus  is 
sparingly  branched,  lobes  flattened,  rigid,  thick,  not 
canaliculate ;  edges  rounded.  Color  gray  to  some- 
what purplish.  Large  discoid  soralia  frequently 
occur  along  the  margin  of  the  lobes.  The  apothecia 
are  small,  marginal,  not  terminal,  and  characterized  by 
a  black  hypothecium,  a  characteristic  not  found  in  any 
other  genera  of  the  family.  Disk  flattened,  dark  to 
black.  The  algae  are  Chroolepus.  These  two  characters 
are  in  contrast  to  the  other  generic  groups  of  the  fam- 
ily and  seem  to  indicate  that  the  genus  is  perhaps  mis- 
placed. As  has  already  been  indicated,  Reinke  and 
others  place  the  group  with  the  Graphidacece.  The 
gross  characters,  however,  indicate  a  relationship  to 
Ramalina* 


PLATI'!  \'.  Fniiicnsf  TviM'.  In  i  lif  pii\ -iic  c. 
i:.  S.  (;i;,y.  naklaii.l.  Calif.  Fim,,  |{,.,|\v. 
lliUiudiiiK  rdinilalii  i>  a  iiiosi  irinaiUalilr  lidir 
in  large  loiin  tiitis.     oftrii  .•..ntii-.-.l  uiili  fsn, 


,(  I 


•tloll    (.f 

(alii. 

InW  iiiix 


GENERA    AND    SPECIES.  163 

The  Rocellas  are  essentially  tropical,  occurring  on 
rock  along  the  sea-coast.  Less  frequently  they  occur 
upon  trees.  The  American  specimens  are  found  prin- 
cipally in  Lower  California. 

1.  Roceila  tinctoria.  Thallus  quite  large,  sparingly 
branched,  lobes  long,  usually  flattened,  but  often  be- 
coming rounded,  gray  to  purplish.  Apothecia  com- 
paratively rare,  lateral,  medium.  Disk  flattened  to 
slightly  convex,  black.  Lateral  white  soralia.  Spores 
colorless,  oblong,  four-celled,  20/x  X  7/x. 

This  lichen  occurs  plentifully  along  the  Mediter- 
ranean coast.  It  occurs,  in  fact,  in  all  tropical  coun- 
tries. Its  uses  as  a  dyeing  agent  have  already  been 
referred  to.  It  also  found  a  use  in  the  treatment  of 
coughs  and  in  diseases  of  the  kidneys.  For  the  latter 
purpose  it  was  largely  collected  from  the  island  of 
Mauritius. 

2.  Roceila  leucophcBa.  Thallus  large,  branching, 
lobes  flattened,  gray.  Apothecia  lateral,  medium  size. 
Disk  flattened,  black.     Lateral  white  soralia.     Spores 

typical,  21/x  X  8/"- 

The  occurrence  and  use  of  this  lichen  are  similar  to 
those  of  R.  tinctoria. 

10.  Evernia. 

There  seems  to  be  considerable  uncertainty  as  to 
the  limitation  of  this  genus.  As  represented  by  the 
two  types  given  below,  there  is  certainly  a  wide  differ- 
ence in  anatomical  characters. 

The  thallus  is  generally  f  ruticose,  large  ;  the  branches 
are  irregularly  angular  and  not  distinctly  flattened. 
The  surface  of  the  thallus  has  the  appearance  of  hav- 


164  GUIDE    TO    THE    STUDY    OF    LICHENS. 

ing  been  besprinkled  with  a  mealy  substance.  Color 
varies  from  yellowish  to  grayish-green  or  bluish-gray. 
Apothecia,  when  present,  are  quite  large,  discoid,  often 
bearing  filiform  thalloid  branches.  Disk  of  a  different 
color  from  the  thallus.  The  spores  are  small,  simple, 
oval,  colorless  ;  resembling  those  of  Cetraria. 

1.  Evernia  furfuracea.  Thallus  large,  much 
branched,  foliose,  but  pendulous  upon  branches  of 
trees ;  bluish-green,  tinged  with  gray ;  channelled 
below,  light-gray.  Usually  sterile.  Apothecia  not 
seen. 

This  lichen  is  striking  in  appearance  and  in  the 
eastern  states  occurs  almost  wholly  upon  pine  trees  in 
mountainous  districts.  It  is  a  handsome,  soft,  pliable 
plant,  which  is  only  very  loosely  attached  to  the 
branches  of  the  tree.  Some  authors  place  it  in  the 
group  Physcia, 

This  species  was  at  one  time  highly  recommended  as 
a  substitute  for  quinine.  It  yields  a  red  dye.  The 
Egyptians  at  one  time  employed  it  in  the  making  of 
bread  and  in  the  preparation  of  hair-powders. 

2.  Evernia  vulpina.  Thallus  large,  typically  fruti- 
cose,  branches  angular,  ridged,  thickness  of  branches 
decreasing  toward  the  top  ;  lemon  color.  Apothecia 
very  large,  terminal  tendency,  margin  and  lower  sur- 
face bearing  thalloid  filaments.  Disk  brown,  concave. 
Spores  colorless,  elliptical,  simple,  7.5/x  X  5.5^. 

This  is  the  noted  "Ulf-mossa"  (Wolf's  moss)  of 
the  Swedes.  It  was  so  named  from  the  popular  belief 
that  the  plant  was  poisonous  to  wolves.  The  lichen 
was  powdered  and  mixed  with  powdered  glass ;   the 


'LATK   IV.    Fnilic.s,.   I'vpc.  ('alif..i-iii:i  Aca.lciny  SfiiMu-e. 

Kcet'niii   ciilpiita.      'i'liis    is  a    t\iiit:illv    wcsit-ni  species, 

and    thoiiuli    trmicti.se    lias  niany    itt    ihc    cliaracteis   of 
foliose  lichens. 


GENERA    AND    SPECIES.  165 

mixture  was  then  smeared  over  some  dead  animal 
placed  in  a  locality  frequented  by  the  wolves.  It  was 
also  used  to  dye  woollen  goods  a  bright  yellow. 

This  is  the  most  showy  and  largest  lichen  found 
along  the  Pacific  coast,  where  it  usually  occurs  fertile  ; 
the  specimens  found  in  the  interior  and  eastern  states 
are  small  and  always  sterile. 

11.  Alectoria. 

This  genus  has  only  a  few  representatives.  The  thal- 
lus  is  typically  fruticose,  long  and  pendulous.  At  the 
joints  the  thallus  is  somewhat  flattened,  otherwise  the 
branches  are  cylindrical.  There  is  a  semblance  to 
Usnea,  but  the  surface  is  smoother  and  the  apothecia 
are  smaller.  The  color  varies  from  light  to  brown 
and  nearly  black.  Oval  soralia  are  c^ten  present. 
The  apothecia  are  few,  sessile,  small  to  medium.  Disk 
flattened  or  convex.  Spores  colorless  to  dark,  simple, 
two  to  four  in  each  spore-sac,  large,  with  thick  outer 
spore-wall.  The  spores  remain  colorless  until  matur- 
ity, when  the  cell-contents  become  dark.  Oil-globules 
are  frequently  present  in  the  spores. 

The  Alectorias  occur  in  arctic  regions  and  upon 
high  mountains.     They  grow  upon  coniferous  trees. 

1.  Alectoria  sarmeyitosa.  Thallus  long,  pendulous, 
branched ;  flattened  at  joints  ;  straw  color ;  surface 
smooth  or  bearing  oval  soralia.  Apothecia  few, 
medium,  lateral.  Disk  light  color  to  brown.  Spores 
typical,  32/u,  X  17.5/x. 

This  plant  is  usually  described  as  A.  ochroleuca  var. 
sarmentosa  ;  also  as  C.  ornicularia  ochroleuca. 


166  GUIDE    TO    THE    STUDY    OF    LICHENS. 

12.  Bryopogon. 

This  group  is  evidently  closely  related  to  Alectoria, 
as  is  indicated  by  the  histological  characters.  The 
thallus  is  long,  pendulous,  typically  fruticose ;  much 
branched,  lobes  cylindrical,  only  slightly  compressed  at 
the  joints.  In  a  transverse  section  of  the  thallus  it  is 
found  to  be  nearly  hollow  in  the  middle,  no  central 
core  being  present  (also  true  of  Alectorid).  Color 
black.  Apothecia  few,  small  to  medium,  lateral. 
Disk  dark,  entire,  somewhat  convex.  Spores  are 
small,  simple,  colorless,  eight  in  each  spore-sac  (nor- 
mal number).  It  must  also  be  kept  in  mind  that  the 
Alectorias  as  well  as  Bryopogons  are  frequently  sterile. 

The  species  occur  upon  rock,  soil,  trees  and  ferns 
in  the  higher  altitudes  and  latitudes. 

1.  Bryopogon  Oregana.  Thallus  comparatively 
small,  more  or  less  erect,  much  branched,  compara- 
tively rigid,  black.  Apothecia  medium,  comparatively 
numerous.  Disk  dark  to  black.  Spores  typical,  6/a 
X  4.5;a. 

2.  Bryopogon  juhata.  Thallus  long,  pendulous, 
much  branched,  branches  long  and  entangled,  some- 
times bearing  soralia,  brown  to  black.  Apothecia 
very  few  or  wanting,  lateral.  Disk  of  same  color  as 
thallus.     Spores  typical  of  the  genus. 

This  is  without  doubt  a  most  striking  lichen.  In 
its  perfect  development  it  resembles  a  tuft  of  woman's 
tresses.  Because  of  such  a  resemblance  it  has  been 
designated  as  "  tree  or  rock  hair."  It  has  also  been 
called  "  horse-tail  lichen,"  but  this  name  is  less  apt 


GENERA    AND    SPECIES.  167 

since    the    thallus  is  less    rigid  than  the  hair  of    the 
horse's  tail. 

B.jubata,  and  perhaps  also  other  species,  yields  a 
red  dye.  Reindeers  feed  upon  it  when  Cladonia  ran- 
giferina  is  not  obtainable.  Laplanders  are  said  to 
cut  down  the  trees  upon  which  it  grows  so  that  the 
reiudeer  may  have  more  ready  access  to  the  lichen. 

13.    Usnea. 

Thallus  fruticose,  pendulous,  large,  much  branched  ; 
lobes  cylindrical,  or  rarely  flattened,  decreasing  in 
size  in  an  acropetal  (toward  apex)  direction.  Main 
branch  quite  thick  and  rigid.  The  surface  is  less 
smooth  than  in  the  thalli  of  Alectoria  and  Bryopogon  ; 
often  it  is  circularly  fissured.  Soralia  are  quite  rare. 
Upon  making  a  transverse  section  of  the  thallus  it  is 
found  to  contain  a  rather  firm  central  core  of  longi- 
tudinal hyphae.  The  prevailing  colors  of  the  thallus 
are  grayish-green,  pale  brownish-green  or  straw  color. 
The  apothecia  are  very  variable  in  size,  lateral  to 
terminal.     Spores  small,  simple,  elliptical,  colorless. 

The  Usneas  are  somewhat  northern  in  their  range. 
They  occur  upon  trees  in  the  higher  altitudes.  Con- 
siderable confusion  exists  as  to  the  limitations  of  some 
species  and  varieties,  as,  for  example,  Usnea  harhata 
and  its  real  or  imaginary  varieties.  The  following 
are  the  more  common  species  irrespective  of  varieties. 

1.  Usnea  linearis.  Thallus  medium,  of  several 
main  branches,  bearing  numerous  long,  slender,  cylin- 
drical branches  ;  greenish-gray.  No  fertile  specimens 
have  come  to  notice. 


168  GUIDE    TO    THE    STUDY    OF    LICHENS. 

By  many  collectors  this  plant  is  designated  as  U» 
harbata.     It  occurs  on  trees  in  proximity  to  U.  barbata. 

2,  Usnea  barbata.  Thallus  medium,  much  branched ; 
branches  comparatively  rigid,  transversely  fissured, 
especially  the  larger  main  branches,  greenish-gray. 
Apothecia  numerous,  very  large,  bearing  filiform 
branches.  Disk  somewhat  concave,  light-brown  color. 
Spores  typical,  8/x  X  5/^* 

This  is  the  "  beard-moss  "  or  "  tree-moss  "  of  poets 
—  the  "  idle  moss  "  of  Shakespeare.  It  is  a  cosmo- 
politan plant;  it  occurs  plentifully  in  the  arctic 
regions  as  well  as  in  the  tropics.  In  some  coun- 
tries it  is  eaten  by  wild  animals  or  is  collected  and 
preserved  as  fodder  for  domestic  animals.  Bertram 
states  that  the  Pennsylvanians  prepared  from  it  an 
orange  dye,  and  Humboldt  states  that  the  South  Ameri- 
cans used  it  for  dyeing  purposes.  In  the  past  ages  it 
enjoyed  an  extensive  use  as  a  remedial  agent.  It  was 
used  as  an  astrigent,  tonic,  diuretic ;  it  was  highly 
recommended  for  whooping-cough,  and  as  an  anodyne. 
It  formed  the  basis  of  hair-powders  and  perfumes  and 
was  thought  serviceable  in  the  preparation  of  explo- 
sives. Boiled  in  beer  it  was  said  to  cure  catarrh 
and  dropsy.  The  Laplanders  used  it  in  the  treatment 
of  scald  head,  and  scrofula  of  children. 

3.  Usnea  longissima.  Thallus  much  elongated, 
branched,  lobes  somewhat  flattened,  greenish-gray. 
Apothecia  rare  or  wanting.     Spores  typical,  9/>(,  X  5/x. 

The  thallus  is  much  longer  than  in  JJ.  barbata,  and 
also  more  slender  and  pendulous.  It  occurs  mostly 
upon  trees  on  high  mountains. 


PLATE  VI.  Fruticoso  Type.  Redwood  Canyon.  Marin 
Co.,  California.  Usnea  harhafn,  tlio  familiar  ••beard 
moss. ' ' 


GENERA    AND    SPECIES. 


169 


VII.     VERR  UCA  RIA  CE^. 

The  representatives  of  this  family  are  characterized 
by  small  globose  apothecia,  which  are  either  immersed 
in  the  substratum  (bark  or  rock)  or  in  the  thallus  {Der- 
matocarpon  and  Endocarpon).  In  the  majority  of 
genera  the  thallus  is  crustose,  even  wholly  hypophloeo- 
dal  or  hypolithic.  Another  characteristic  of  the  fam- 
ily is  the  indistinct,  slender,  gelatinized  paraphyses. 

With  the  exception  of  Endocarpon  the  members  of 
the  family  are  insignificant  in  appearance;  in  fact, 
some  are  very  doubtful  lichens,  as,  for  example,  most 
of  the  Pyrenulas  and  some  species  of  Trypethelium. 

Two  algal  types  exist  in  this  family:  Ghroolepus 
occurs  in  the  genera  from  Trypethelium  to  Verrucaria, 
Pleurococcus  occurs  in  Verrucaria,  Dermatocarpon 
and  Endocarpon.  It  must,  however,  be  born  in  mind 
that  the  algal  symbiont  may  vary  in  different  in- 
dividuals of  the  same  species.  This  change  in  sym- 
bionts  requires  further  study. 

KEY  TO  THE  GENERA. 

Crustose  thallus.  ,  ,      ^  , 

Thallus  scarcely  visible,  mostly  hypophloeodal.        < 
Spores  six   to  eight-celled,  colorless  .     1.  Trypethelium. 

Spores  four-celled,  brown 2.  Pyrenula. 

Spores  many-celled,  colorless     .    .     .     3.  Conotrema. 
Spores  multilocular,  colorless. 

Spore-wall  normal 4-  Thelolrema. 

Spore-wall  thick 5.   G/postomum. 

Thallus  visible,  mostly  epiphloeodal  or  epilithic. 
Spores  simple,  colorless. 

Medium  size       ^-   lerrucana. 

Very  large ^-  Pertusario. 

Foliose  thallus.^ntiro ;  spores  colorless. 

Spores  multilocular:  thallus  minute      .     S.  Dermatocarpon. 
Spores  simple ;  thallus  large     .     .     .     .     9.  Endocarpon, 


170  GUIDE    TO    THE    STUDY    OF    LICHENS. 

1.    Trypethelium. 

The  thallus  is  hypophloedal  during  its  entire  existence. 
It  consists  simply  of  a  deficient  network  of  hyphse  en- 
closing a  few  algae  (^Chroolepus).  The  bark  over  the 
apothecia  and  thallus  is  smooth  and  of  a  rusty-red 
color  which  gradually  fades  into  brownish  or  green- 
ish. 

The  apothecia  are  likewise  hypophloeodol,  and  occur 
in  clusters  of  from  five  to  forty.  Each  apothecium  is, 
however,  independent  of  its  neighbors,  and  may  be 
considered  as  an  individual  of  the  colony.  As  the 
apothecia  grow,  they  push  up  the  superimposed  bark 
mi  til  it  forms  a  more  or  less  irregular  elevation.  The 
spores  escape  through  minute  apical  pores. 

The  spores  are  normally  colorless  and  eight-celled, 
spindle-shaped ;  the  plasmic  masses  diamond-shaped. 

The  genus  is  essentially  southern.  The  representa- 
tives occur  upon  trees.  Some  authors  combine  it  with 
Pyrenula. 

li  Trypethelium  virens.  Bark  above  thallus  smooth, 
light-brown  to  pale-green.  Apothecial  colonies  con- 
sist of  from  ten  to  forty  minute  apothecia.  Perithe- 
cium  black.  Spores  colorless,  six  to  eight-celled, 
42/x  X  10/x. 

Bark  is  tinged  reddish  or  rusty  brown,  over  and 
about  the  apothecia.  Nearly  all  of  the  so-called 
species  of  Trypethelium  require  further  study. 

2.  Pyrenula. 

This  is  another  lowly-organized  lichen-genus.  The 
thallus  as  well  as  the  apothecia  are  hypophloeodal,  and 


GENERA    AND    SPECIES.  171 

morphologically  resemble  similar  structures  of  the  pre- 
ceding genus.  Sometimes  tlie  apothecia  occur  singly, 
but  they  also  occur  in  colonies.  The  perithecium  is 
black.  The  spores  are  usually  colored  dark,  four-celled, 
otherwise  resembling  those  of  Trypethelium. 

The  representatives  of  this  genus  are  mostly  south- 
ern in  their  range.  They  occur  upon  the  smoother 
barks.  In  many  the  thallus  is  very  rudimentary,  so 
that  the  algae  (Chroolepus)  can  only  be  found  after 
careful  search. 

1.  Pyrenula  aspistea.  Bark  over  thallus  brown, 
smooth.  Apothecia  small,  numerous,  black.  Spores 
typical,  constricted  at  transverse  septa,  17/u,  X  8.5/x. 

2.  Pyrenulu  nitida.  Bark  over  thallus  greenish  or 
yellowish-brown.  Apothecia  larger,  fewer,  and  more 
scattered  than  in  P.  aspistea,  black.  Spores  typical, 
not  constricted,  14/a  X  7.5/x. 

3.   Conotrema. 

The  thallus  is  in  part  epiphloeodal,  thin,  evenly 
spreading  to  indistinctly  areolate.  The  alga?  are  Pro- 
tococcus  instead  of  Chroolepus.  The  apothecia  are 
urn-shaped,  less  hypophloeodal  than  in  Pyrenula  and 
larger.  They  break  through  the  superimposed  bark 
and  have  distinct  apical  pores  from  which  the  spores 
escape.  Disk  light  color.  Spores  are  long,  filament- 
ous, with  numerous  transverse  septa ;  when  once  seen 
they  will  not  be  mistaken. 

The  genus  requires  further  study ;  only  one  species 
has  come  to  notice ;  it  occurs  upon  trees,  those  of 
the  smoother  barks,  as  Betula  and  Acer. 


172  GUIDE    TO    THE    STUDY    OF    LICHENS. 

1.  Conotrema  urceolatum.  Epiphloeodal  portion  of 
thallus  evenly  spreading,  thin,  whitish.  Apothecia 
urn-shaped  when  fully  matured,  partially  enclosed 
by  thallus.  Disk  of  a  waxy  color,  margin  black. 
Spores  typical  of  genus,  140/x,  X  V- 

^.    Thelotrema. 

As  in  Conotrema,  the  thallus  is  rudimentary  and 
partly  hypophloeodal.     The  algag  are  Chroolepus. 

The  apothecia  are  characteristic.  They  resemble  a 
miniature  volcanic  crater.  They  are  numerous  and 
quite  uniformly  scattered  over  the  thallus.  Upon  ex- 
amining the  opening  at  the  top  the  whitish  perithecium 
can  be  seen  within ;  that  is,  the  perithecium  becomes 
separated  from  the  more  inflexible  cone.  A  whitish, 
waxy  coloration  pervades  the  entire  plant. 

The  spores  are  large,  colorless,  multilocular,  spindle- 
shaped,  with  a  thick  rugose  spore-wall. 

There  is  a  considerable  number  of  species  which 
occur  upon  trees  in  the  warmer  latitudes. 

1.  Thelotrema  lepadinum.  Thallus  thin,  uniformly 
spreading,  smooth,  white  to  cream  color.  Apothecia 
usually  numerous,  conical,  immersed,  with  a  circular 
opening  through  which  the  light-colored  perithecium 
can  be  seen.  Spores  large,  colorless,  spindle-shaped, 
12  to  16  transverse  septa,  and  a  few  longitudinal  septa 
at  the  middle.     Spore-wall   thick,  rugose,  51^  X  13/x. 

5,    Gyrostomum. 

Thallus  rudimentary.  Apothecia  quite  small  and 
semi-globose.     Both  thallus  and  apothecia  begin  their 


GENERA    AND    SPKCIES.  173 

development  below  the  surface  of  the  substratum. 
The  apothecia  at  maturity  open  by  an  apical  pore  which 
renders  them  urn-shaped.  The  perithecium  is  black. 
The  spores  are  colorless,  multilocular,  with  a  thick 
gelatinous  outer  spore-wall  which  is  not  rugosely 
folded. 

Only  one  species  came  to  my  notice,  which  is  south- 
ern and  grows  upon  various  trees. 

1.  Gyrostomum  scyphidiferum.  Thallus 'rudiment- 
ary, uniformly  spreading,  greenish-gray  to  brownish. 
Apothecia  small,  somewhat  urn-shaped  when  mature. 
Disk  dark    to  black.     Spores    typical   of    the   genus, 

35)u,  X  13/X-. 

6.    Verrucaria. 

Thallus  distinctly  crustose  and  mostly  epilithic  or 
epiphloeodal.  It  begins  its  development,  however,  be- 
low the  surface  of  the  substratum.  In  the  rock-species 
the  thallus  begins  its  development  upon  the  surface, 
but  the  lichen-acids  disintegrate  the  rock,  and  the 
greater  portion  of  the  thallus  (hypha?)  becomes  im- 
bedded in  the  loosened  particles.  The  algie  are  evi- 
dently Fleurococcus,  though  some  authors  report 
Chroolepus  as  the  generic  alga. 

The  apothecia  are  small,  globose,  more  or  less  im- 
mersed in  the  thallus  and  substratum,  perithecium 
dark  or  black.  The  paraphyses  and  spore-sacs  are 
much  gelatinized  ;  so  much  so  that  they  are  scarcely 
discernible.  The  spores  are  simple,  elliptical,  color- 
less, and  thin-walled.  They  generally  bear  oil-glob- 
ules. 

The  Verrucarias  have  a  wide  range,  and  occur  upon 


174  GUIDE    TO    THE    STUDY    OF    LICHENS. 

rock,  perhaps  rarely  upon  trees.     The  majority  of  so- 
called  tree   Verrucarias  belong  to  other  genera. 

1.  Verrucaria  rupestris.  Thallus  deficient,  dark 
or  dirty  color.  Apothecia  small,  partially  immersed ; 
perithecium  black.     Spores  typical,  15/x  X  6.5/x. 

2.  Verrucaria  pyrenophora.  Thallus  rudimentary, 
uniformly  spreading,  gray.  Apothecia  small,  raised 
above  the  thallus.  Disk  somewhat  flattened,  black. 
Spores  not  found. 

3.  Verrucaria  nigrescens.  Thallus  granular  to  in- 
distinctly areola te,  dirty  gray  to  nearly  black.  Apo- 
thecia numerous,  medium  size,  black.  Spores  typical, 
12/A  X  7.5/x. 

^.  Verrucaria  muralis.  Tliallus  indistinctly  areo- 
late,  light  to  pale  brown.  Apothecia  numerous.  Disk 
projecting  somewhat  above  thallus,  black.  Spores 
typical,  13/A  X  8/ix. 

This  lichen  frequently  occurs  on  brick,  mortar,  lime- 
stone, etc. 

5.  Verrucaria  fuscella.  Thallus  comparatively 
thick,  distinctly  areolate,  dirty  gray  to  nearly  black. 
Apothecia  small,  immersed,  black.  Spores  typical, 
13.5/x  X  6.5/x. 

6.  Verrucaria  margacea.  Thallus  thick,  areolate, 
surface  smooth ;  clay  color.  Apothecia  numerous, 
almost  entirely  immersed,  black.  Spores  large,  pale 
yellowish,  otherwise  typical,  30/>t  X  13.5/li. 

7.  Pertusaria. 

Thallus  crustose,  but  more  highly  developed  than 
in  Verrucaria,  though  it  varies  considerably  in  thick- 


GENERA    AND    SPECIES.  175 

ness.  Its  color  varies  from  gray  to  greenish-gray. 
The  algae  are  Protococcus.  Soralia  are  quite  common 
and  seem  to  attain  a  high  development  in  this  genus. 
Darbishire,  who  has  made  a  special  study  of  the  soralia 
of  the  Pertusarias,  is  inclined  to  the  view  that  they 
are  phylogenetically  derived  from  apothecial  structures. 

The  apothecia  are  globose  and  immersed  in  warty 
elevations  of  the  thallus.  Usually  there  is  no  percep- 
tible pore-opening.  Absence  of  any  marked  coloration 
of  the  apothecia  is  characteristic.  Spores  are  simple, 
large,  colorless,  one  or  two  in  each  spore-sac.  The 
inner  spore-wall  is  reticulately  marked  in  some  species  ; 
oil-globules  are  often  present. 

Most  of  species  are  cosmopolitan  ;  they  occur  upon 
bark  and  rock,  less  commonly  upon  moss. 

1.  Pertusaria  pustulata.  Thallus  very  deficient, 
grayish.  Apothecia  entirely  immersed  in  the  substra- 
tum, producing  pustular  elevations  and  finally  opening 
by  a  minute  apical  pore.  Spores  typical,  but  inner 
wall  not  reticulate,  75/x,  X  43/x. 

2.  Pertusaria  leioploca.  Thallus  deficient  of  scat- 
tered apothecial  warts,  greenish-gray  to  yellowish- 
brown.  Apothecia  wholly  immersed  in  the  warts. 
Spores  typical  (nor  reticulate),  usually  four  to  six  in 
each  spore-sac,  60/m  X  22/i. 

3.  Pertusaria  multipuncta.  Thallus  usually  entire, 
somewhat  fissured,  sometimes  rugose  or  areolate,  pale 
ash-gray.  Apothecia  immersed  in  thalline  warts, 
single  or  confluent.  Spores  typical,  inner  spore- wall 
reticulate,  15CV  X  60/>t. 

Jf..  Pertusaria  glohularis.     Thallus  thin,  apothecial 


176  GUIDE    TO    THE    STUDY    OF    LICHENS. 

warts  united  in  groups  of  from  two  to  six  ;  gray.  Apo- 
thecia  entirely  immersed,  small  pore  often  visible. 
Spores  typical  but  not  reticulate,  95^  X  33/x. 

5.  Pertusaria  glomeridata.  Thallus  consists  of 
numerous  confluent  apothecial  warts,  nearly  white  to 
gray.  Apothecia  immersed,  opening  by  small  pores. 
Spores  typical,  inner  wall  reticulate,  loO/x  X  60/x. 

6.  Pertusaria  communis.  Thallus  thick,  rugose 
and  somewhat  fissured,  gray.  Apothecia  in  groups, 
immersed  in  apothecial  warts,  apical  pore  present. 
Spores  typical,  inner  wall  reticulate,  1 50/x  X  47/*. 

This  species,  as  well  as  other  species  of  the  genus, 
were  formerly  included  among  the  PseudoUchenes  or 
Lichenes  imperfecti,  under  the  name  of  Variolaria. 
P.  com.  contains  a  large  percentage  of  oxalate  of  lime 
and  had  been  used  in  France  as  the  source  of  oxalic 
acid.  It  was  used  as  a  remedy  in  feyers  and  as  an 
astringent  in  intestinal  troubles.  Many  Pertusarias 
were  more  or  less  recommended  in  the  dyeing  industries. 

1.  Pertusaria  velata.  Thallus  thick,  areolate,  light- 
gray.  Apothecial  warts  bearing  apothecia  which 
open  by  apical  pores  showing  the  pale  disk.  Spores 
yery  large,  typical,  but  not  reticulate,  180/x,  X  65/x. 

8.  Dermatocarpon. 

The  only  representatiye  of  this  genus  which  came  to 
notice  is  generally  included  in  the  genus  Endocarpon. 

The  thallus  is  yery  minute  for  a  foliose  type.  Care- 
ful search  with  a  pocket  lens  is  necessary  to  detect  it. 
It  consists  of  a  single  entire  lobe  closely  adnate  to  the 
substratum  (rock)  and  is  of  a  dark  color.     Several  of 


I'LATK  Ir.  Cruslosc  'l^vpos.  Kr..iii  ihc  i-(«ii»'i'i  k.ii  oi  \. 
Y.  Chirk  in  tlie  liriliariiim  nt  ilir  (  alifoiiiia  Ai'utleiiiy  oi 
Scieiii'*'.      I'ertitsKriii  vrlafn. 


GENERA    AND    SPECIES.  177 

these  minute  lobes  usually  occur  in  close  proximity. 
The  algje  are  Pleurococcus  as  in   Verrucaria. 

The  apothecia  are  very  small,  usually  one  is  im- 
mersed in  each  thallus-lobe-  Quite  generally  minute 
single-celled  algse  {^Pleurococcus'^)  occur  above  the 
thecium ;  these  are  known  as  thecial  algse,  and  are 
ejected  with  the  spores  and  enter  into  a  symbiotic  re- 
lationship with  the  germinating  spore.  The  spores 
are  colorless,  multilocular,  thus  differing  from  those  of 
Verrucaria  and  Endocarpon. 

The  only  species  occurs  upon  limestone,  and  seems 
to  be  southern  in  its  range. 

1.  Dermatocarpon  pusillum.  Thallus-lobes  entire, 
minute,  widely  scattered,  closely  adnate  to  the  substra- 
tum, dark.  Apothecia  typical  of  the  genus.  Spores 
typical,  two  or  three  in  each  spore-sac,  23.5/x  X  18.5/x. 

9.  Endocarpon. 

In  this  genus  the  thallus  is  large,  typically  foliose, 
entire ;  attached  by  a  central  portion  (umbilicus)  con- 
sisting either  of  a  single  lobe  or  numerous,  more  or 
less  plicate,  lobes.  The  thallus  is  quite  thick  and  rigid 
and  much  less  brittle  than  in  Umbilicaria  and  Gyro- 
phora.     Color  gray  to  dark-gray. 

The  apothecia  are  small,  globose  and  entirely  im- 
mersed in  the  thallus,  opening  by  small  dark  pores, 
which  are  scattered  over  the  thallus.  The  spores  are 
simple,  colorless,  elliptical,  the  usual  number  (8)  oc- 
curring in  each  spore-sac. 

The  Endocarpons  occur  principally  upon  rock,  also 
upon  soil  and  the  bark  of  trees. 


178  GUIDE    TO    THE    STUDY    OP    LICHENS. 

1.  JEndocarpon  hepaticum.  Thallus  of  orbicular 
scattered  entire  lobes,  variable  in  size,  closely  ad- 
nate  to  substratum  (soil),  margin  turned  upward, 
pale  flesh  color,  changing  to  dark-brown ;  soralia  some- 
times present.  Apothecia  immersed.  Spores  typical, 
13.5ya  X  V 

The  color  of  the  thallus  is  very  likely  due  to 
the  presence  of  oxide  of  iron  taken  up  from  the 
soil. 

2.  Enndocarpon  arhoreum.  Thallus  quite  large, 
somewhat  lobate,  margin  usually  turned  downward, 
attached  by  numerous  long  black  rhizoids,  upper 
surface  gray  to  light-brown ;  lower  surface  dark. 
Apothecia  immersed,  scattered.  Spores  typical,  13/x 
X5/X. 

3.  Endocarpon  Jluviatile.  Thallus  quite  large, 
lobate  at  margin,  only  loosely  attached  to  substra- 
tum, upper  surface  gray  to  dark ;  lower,  gray  to  brown  ; 
few  rhizoids.     Apothecia  not  seen. 

Jf..  Endocarpon  miniatwn.  Thallus  large,  entire, 
attached  by  an  umbilicus,  upper  surface  smooth,  gray 
to  dark ;  lower  surface  pustulate,  dark  to  black,  with 
numerous  fine  rhizoids.  Apothecia  immersed  and  uni- 
formly scattered,  appearing  as  minute  dark  specks. 
Spores  typical,  13.5/x  X  5/x. 

The  pustules  on  the  lower  surface  prove  on  exami- 
nation to  be  apothecia,  bearing  spores.  A  so-called 
variety  consists  of  numerous  imbricate  ascending  lobes 
instead  of  a  single  thallus. 

A  coloring  substance  is  extracted  from  this  lichen, 
which  is,  however,  said  to  be  of  an  inferior  quality. 


GENERA    AND    SPECIES.  179 

VII I.     COLLEMACEJS. 

This  family  is  characterized  by  a  foliose,  dark-blue 
thallus,  which  is  highly  gelatinous  when  moist.  As  a 
rule,  the  thallus  is  thin  and  more  or  less  lobate,  at- 
tached by  an  umbilicus.  The  surfaces  are  frequently 
rugosely  folded.  Soralia  are  deficient.  Rhizoids  are 
also  deficient  excepting  in  the  genus  Mallotium.  The 
algai  are  Nostoc,  excepting  perhaps  in  Hydrothyria. 
In  all  cases  they  are  bluish-green,  and  occur  in  chains. 
This  one  character  alone  suffices  to  mark  the  repre- 
sentatives of  the  family.  Owing  to  the  supposition 
that  the  algae  are  not  arranged  in  such  well-defined 
layers  as  in  the  other  foliose  forms  these  lichens  are 
spoken  of  as  homoimerous.  The  algae  are,  however, 
arranged  in  more  or  less  definite  layers,  especially  in 
the  groups  above  Collema. 

The  apothecia  are  rather  small,  discoid  and  sessile 
upon  the  thallus.  Spores  vary  in  form  and  septation, 
and  are  mostly  colorless. 

KEY  TO  THE   GENERA. 

Cortical  layers  wanting 1.  Collema. 

Cortical  layers  present. 

Rhizoids  deficient,  thallus  thin. 

Lower  surface  of  thallus  not  veined      .     2.  Leptogium. 
Lower  surface  of  thallus  veined   .     .     .     3.  Hydrothyria. 
Rhizoids    long,    numerous,   thallus  com- 
paratively thick 4'  Mallotium. 

1.  Collema, 
This  genus  is  represented  by  many  species.     The 
thallus  varies  from  small  and  almost  fruticose  to  quite 
large    and  typically  foliose.     The  amateur  will  have 


180  GUIDE    TO    THE    STUDY    OF    LICHENS. 

no  trouble  in  recognizing  the  more  typical  representa- 
tives. The  dark-blue  to  almost  black  gelatinous 
(when  moist)  thin  thallus  is  characteristic ;  these 
general  characteristics,  however,  also  apply  to  Lepto- 
gium.  Upon  a  microscopical  examination  it  is  found 
that  no  cortical  structure  is  present  in  Collema.  The 
algae  {Nostoc)  and  hyphae  are  loosely  intermingled. 
The  margin  of  the  thallus  is  more  or  less  divided  or 
lobed. 

The  apothecia  are  small  to  medium  in  size,  discoid, 
sessile  upon  the  thallus.  Disk  concave,  flattened  or 
slightly  convex,  usually  brown  or  reddish-brown. 

The  spore-characters  are  very  variable.  They  may 
be  simple,  two  to  many-celled  and  multilocular.  Upon 
further  careful  study  it  will  no  doubt  be  possible  to 
subdivide  the  genus  upon  its  spore-differences.  Usually 
the  spores  are  colorless  ;  faintly  colored  spores,  how- 
ever, occur. 

The  Collemas  occur  upon  soil,  bark,  rock,  and  are 
even  found  partially  or  wholly  submerged  in  water. 
They  seem  to  be  somewhat  western  in  their  raia^e ;  they 
are,  however,  also  common  sooth  and  east. 

1.  Collema  pycnocarpiim.  Thallus  medium,  ascend- 
ing lobes  divided  and  narrowed ;  from  yellowish-brown 
at  the  base  to  dark-blue  green  above.  Apothecia  very 
numerous,  terminal  and  marginal  margin  not  elevated. 
Disk  convex,  reddish-brown  to  dark-brown.  Spores 
two-celled,  colorless,  elliptical,  13.5/x  X  6.5/x,. 

2.  Collema  cyrtaspis.  Thallus  much  as  in  C.  pycno- 
carpum,  larger  and  darker  in  color.  Apothecia  some- 
what larger,  crenate  margin  raised  above  the  flattened 


GENERA    AND    SPECIES.  181 

dark-brown  disk.     Spores  four  to  six-celled,  colorless, 
spindle-shaped,  16/i,  X  ^f"- 

3.  CoUema  myriococcum.  Thallus  medium,  lobes 
ascending,  more  or  less  flexed  and  folded,  surface 
somewhat  granular  or  warty,  dark-blue  to  black. 
Apothecia  not  seen,  said  to  be  small,  numerous  and 
somewhat  immersed.  Spores  simple,  colorless, 
Ufx  X  8/x. 

4.  Collema  leucopepla.  Thallus  thin,  lying  flat  upon 
the  substratum,  rather  indistinctly  lobate,  wrinkled 
above  and  below,  often  granular  ;  dark-green  above, 
somewhat  paler  beneath.  Apothecia  rather  small. 
Disk  reddish-brown,  with  a  translucent  whitish  tinge. 
Spores  acicular,  four  to  six-septate,  51/a  X  3/x. 

5.  Collema  nigresceiis.  Thallus  much  as  in  C.  leu- 
copepla. Apothecia  small,  numerous.  Disk  flattened 
to  convex,  dark-brown.  Spores  acicular,  resembling 
those  of  Bacidea,  four  to  six-septate,  35/x  X  3yu,. 

6.  Collema  ryssoleum.  Thallus  large,  thin,  lobes 
ascending ;  wrinkled  and  rugosely  folded  above,  reticu- 
late below  ;  dark-green  above,  somewhat  paler  beneath. 
Apothecia  small,  much  as  in  C.  nigrescens.  Spores 
colorless,  spindle-shaped,  21/a  X  6.5/x. 

7.  Collema  pulposum.  Thallus  medium,  compara- 
tively thick,  lobes  imbricate  and  somewhat  ascending, 
smooth,  margin  crenulate ;  leek-green  to  dark.  Apo- 
thecia large,  numerous,  margin  crenate  and  warty,  ex- 
tending above  the  concave  brown  disk.  Spores  color- 
less, spindle-shaped  to  ovoid,  elliptical,  four  to  six- 
celled,  rarely  multilocular,  21/x  X  7.5/x. 

8.  Collema  laciniatum.     Thallus  rather  small,  lobes 


182        '  GUIDE    TO    THE    STUDY    OF    LICHENS. 

long,  margin  bearing  short  small  branchlets ;  dark 
above,  lighter  beneath.  Apothecia  numerous,  on  short 
thalloid  branches,  margin  somewhat  crenulate,  dark. 
Disk     dark.      Spores     colorless,     two-celled,     small, 

9.  Collema  pUcatile.  Thallus  comparatively  small, 
lobes  narrowed,  ascending,  margin  somewhat  crenu- 
late ;  nearly  black  above,  somewhat  less  dark  beneath. 
Apothecia  small,  on  short  thalloid  branches,  margin 
somewhat  raised.  Disk  nearly  black.  Spores  multi- 
locular,  oblong,  irregular  outline,  constricted  at  the 
septa,  24/t  X  6/x. 

10.  Collema  crispum.  Thallus  medium  size,  com- 
paratively thick,  margin  thickened  and  indistinctly 
crenulate  ;  dark  above,  less  dark  beneath.  Apothecia 
numerous,  marginal,  cup-shaped,  margin  crenulate  and 
warty.  Disk  dark-brown.  Spores  multilocular,  color- 
less, somewhat  constricted  at  septa,  27yw,  X  12/x. 

11.  Collema  Jlaccidum,  Thallus  large,  lobes  large, 
only  slightly  ascending,  more  or  less  folded  and  warty ; 
dark-blue,  lighter  beneath.  Apothecia  small,  upon 
surface  of  thallus,  margin  entire  and  raised  above  the 
reddish-brown  disk.  Spores  colorless,  four  to  six- 
celled,  23/x  X  6/x. 

2.  Leptogium. 

The  thallus  resembles  the  thallus  of  Collema.  It  is 
somewhat  larger,  thicker,  and  more  rigid.  The  essen- 
tial difference  is  made  apparent  upon  a  microscopical 
examination.  In  Leptogium  there  is  a  cortical  struct- 
ure consisting  of  a  single  row  of  cells.  This  cortical 
tissue  is  more  highly  developed   in    the   apothecium, 


GENERA    AND    SPECIES.  183 

where  it  attains  considerable  thickness,  otherwise 
the  apothecia  are  as  in  Collema.  The  spores  liave 
tlie  general  characters  of  the  spores  in  Collema. 

There  can  be  little  doubt  that  this  genus  is  simply  a 
somewhat  higher  evolution  than  Collema.  The  two 
genera  correspond  in  habitat  and  range. 

Although  a  considerable  number  of  species  are 
known,  we  shall  content  ourselves  with  the  description 
of  a  single  species. 

1.  Leptogium  chloromelum.  Thallus  medium  to 
large,  much  wrinkled  and  folded,  margin  of  lobes 
turned  upward,  bearing  numerous  isidioid  outgrowths, 
dark-green.  Apothecia  medium,  margin  somewhat 
elevated,  slightly  rugose.  Disk  dark-brown.  SjDores 
colorless,  multilocular,  granular,  20/a  X  12/x. 

3.  Hydroihyria. 

Thallus  quite  large,  flat,  lobed,  dark ;  distinctly 
veined  below.  The  veins  are  simply  bundles  of 
hyphasi.  The  genus  is  represented  by  one  species 
only.  It  is  peculiar  in  that  its  habitat  is  on  rock  in 
clear  running  water,  in  which  position  it  matures  its 
spores.  As  a  rule,  lichens  do  not  thrive  in  very  moist 
places.  Some  doubt  exists  as  to  the  nature  of  the 
symbiotic  algic.  Some  authors  maintain  that  they  are 
Rlvularia.  They  certainly  are  not  normal  Rivularia  ; 
it  is  likely  that  they  are  modilied  Nostoc.  Further 
study  is  necessary  to  determine  tliis  ])oinr. 

1.  Hydrothyria  venosa.  Tliallus  large,  tliin,  lobes 
large,  smootlu  dull  gray  when  dry  ;  somewhat  paler 
beneath  and  bearing  branching  veins.     Apothecia  few, 


184  GUIDE    TO    THE    STUDY    OF    LICHENS. 

medium,  usually  marginal,  margin  not  raised.  Disk 
convex,  reddish-brown.  Spores  colorless,  four-celled, 
oblong,  elliptical,  granular  contents,  30yu  X  7^. 

This  rather  rare  and  highly  interesting  lichen  has 
been  found  in  the  New  England  States  and  in  Cali- 
fornia. 

Jf..  Mallotium. 

The  thallus  of  this  genus  indicates  a  higher  develop- 
ment than  Leptogium  ;  it  is  thicker  and  larger ;  it  fre- 
quently bears  soralia  or  soredia ;  its  cortical  tissues  are 
more  highly  developed.  Color  is  dark-blue.  The 
lower  surface  bears  numerous  very  long  delicate  rhi- 
zoids.     The  algee  are  JVostoc. 

The  apothecia  are  similar  to  those  of  Collema  and 
Leptogium.  As  a  rule,  the  few  representatives  which 
occur  in  the  United  States  are  found  to  be  sterile. 

They  occur  upon  trees  and  rocks,  and  range  from 
north  to  south,  though  they  are  quite  rare.  Generally 
Mallotium  is  classed  with  Leptogium.  As  a  genus  it 
requires  further  study. 

1.  Mallotium  saturninum.  Thallus  large,  quite 
thick,  nearly  monophyllous,  margin  lobate ;  upper  sur- 
face granular,  dull  gray  to  dark-blue  ;  lower  surface 
bearing  long,  slender,  grayish  rhizoids.     Apothecia  not 

seen. 

IX.  PANNARIACE^. 

Considerable  uncertainty  exists  as  to  the  limitations 
of  this  family  ;  genera  are  included  which  seem  to  have 
no  possible  genetic  relationship  to  other  genera  {Ephehe, 
Lichina).  The  algal-characters  vary  greatly,  and  have 
been  made  the  basis  of  the  generic  determination.     The 


GENERA    AND    SPECIES.  185 

characters  of  the  thalhis  also  vary  greatly ;  the  smaller 
and  more  insignificant  forms  are  fruticose  ;  the  higher 
forms  are  foliose.  This  seems  to  be  contradictory  to 
the  arrangement  of  the  Parmeliacece,  in  which  family 
the  fruticose  forms  are  placed  highest.  Upon  close 
examination  it  is,  however,  very  evident  that  the  fruti- 
cose forms  of  the  Pannariacece  are  very  lowly  organ- 
ized as  lichens. 

The  algae  of  this  family  are  blue-green,  with  the  ex- 
ception of  those  of  Psoroma  and  Sticta  in  which  genera 
they  are  bright-green.  As  regards  spore-characters, 
the  only  thing  that  can  be  stated  here  is  that  none  are 
multilocular  and  that  th^y  are  not  very  large  ;  most  of 
them  are  colorless.  The  apothecial-characters  are  as 
variable  as  the  thallus-characters. 

KEY  TO   THE    GENERA. 

Symbiotic  algae  {Sirosiphon)  forming  the 
bulk  of  the  thallus-structure  of 
minute  brandling  filaments  ,  .  1.  Ephehe. 
Symbiotic  algae  (not  Sirosiphon)  not  form- 
ing the  bulk  of  the  thallus  struc- 
ture. 

Thallus  crustose,  dark 2.  Lecofhecium. 

Thallus  fruticose,  dark,  minute. 

Cortical  tissue  \v;vnting,  spores  simple. 

Algae  in  chains  {Rivularia)     .     .     .     .     3.  Lichina. 

Algae  singly  ( Gloeocapsa) 4.   Omphalaria. 

Cortical    tissue    present,     spores    two- 
celled,  colorless 5.  Polychidium. 

Thallus  folio«e. 

Spores  simple,  colorless. 
Apothecia    innate    in   depression   of 

thallus 6.  Heppia. 

Apothecia  discoid,  sessile. 
Algae    singly,  bright -green  {Proto- 

coccus) 7.  Psoroma. 

Algae  in  colonies,  blue-green  (Poly- 
coccus)   ,     .     .     .     .     S.  Pannaria. 


186  GUIDE    TO    THE    STUDY    OF    LICHENS. 

Spores  not  simple. 
Apothecia  innate  upon  upper  surface 
of  thallus. 
Spores  acicular,  4-6  celled,  colorless     9.  Peltigera. 
Spores  two-celled,  elliptical,  brown  10.  Solo'rina. 
Apothecia  innate  upon  lower  surface 

of  upturned  lobes 11.  Nephromium. 

Apothecia  discoid,  sessile,  spores  acic- 
ular, 4-6  celled. 
Algae  blue-green  (Polycoccus)      .     .  12.  Stictina. 
Algae  bright-green  (Protococcus)      .  13.  Sticta. 

1.  Ephehe. 

This  genus  evidently  does  not  belong  to  this  family 
since  it  has  nothing  in  common  with  the  other  genera. 
The  thallus  is  very  minute,  fruticose  and  dark  in  color. 
It  consists  of  an  alga  {Sirosiphon  pulvinatus)  which  is 
branching  and  through  which  the  hyphas  of  the  fungal 
symbiont  ramify.  In  that  respect  it  is  highly  different 
from  any  other  lichen-group ;  that  is  the  alga  forms 
the  supporting  and  protecting  structure  while  the 
fungus  is  the  protected  symbiont. 

The  Ephehes  occur  upon  rock  in  moist  places.  It 
is  in  most  instances  very  difficult  to  decide  whether 
the  plant  be  Ephehe  or  the  alga  Sirosiphon  pulvinatusj 
which  is  exactly  similar  in  form  and  in  its  habitat. 
Very  frequently  the  plant  bears  spermagonia  which  at 
once  proves  it  lichen-nature.  I  am  even  of  the 
opinion  that  the  spermagonia  are  the  fungal  sym- 
bionts ;  these  appear  as  semi-translucent  swellings 
along  the  side  of  the  branches.  A  good  pocket- 
lens  is  necessary  to  make  out  the  structure  of  the 
Ephehes. 

1.  Ephehe  puhescens.  Thallus  minute,  much 
branched,  rigid  when  dry,  more   or  less    decumbent, 


GENERA    AND    SPECIES.  187 

dark  to  nearly  black.     Spermagonia  sometimes  numer- 
ous. 

Considerable  material  from  widely  different  localities 
has  been  examined,  but  no  apothecia  have  been  found. 
It  is  perhaps  always  sterile  in  this  country.  Lindsay 
and  others  report  it  as  apothecia-bearing  in  Europe. 
Bornet,  the  noted  French  lichenologist,  states  that  it 
is  dioeciaus,  that  is,  the  male  reproductive  organs  (sper- 
magonia) occur  upon  one  plant,  while  the  female  or- 
gans (apothecia)  occur  upon  another  plant.  It  seems 
to  be  an  undecided  question  whether  Ephehe  puhescens 
is  a  genuine  lichen  ;  it  is  perhaps  only  an  alga  (^S.  pul- 
vinatus)  parasitically  associated  with  fungi  (sperma- 
gonia and  apothecia). 

Tuckerman  reports  two  more  species,  E.  mammiUo- 
sum  and  E.  solida,  both  of  which  are  said  to  resemble 
the  one  described. 

2.  Lecothecium. 

Thallus  crustose  to  perhaps  minutely  foliose,  dark, 
closely  adnate  to  substratum.  The  algoe  are  bluish- 
green  and  occur  in  chains  {Rivularia  nitida). 

The  apothecia  are  of  medium  size,  discoid,  sessile  or 
partially  immersed.  The  hypothecium  is  usually  dark, 
sometimes  blue-black.  The  spores  are  few,  variable 
in  size  and  form,  due  to  the  fact  that  but  few  attain 
maturity.  Wlien  mature  they  are  oblong,  colorless, 
four-celled. 

Only  a  few  representatives  are  known  in  this  coun- 
try, they  occur  in  the  arctic  regions  and  the  north 
temperate  zone.  They  grow  upon  rock  or  sandy 
soil. 


188  GUIDE    TO    THE    STUDY    OF    LICHENS. 

1.  Lecothecium  nigrum.  Thallus  crustose,  granular, 
indistinctly  areolate,  nearly  black.  Apothecia  small, 
somewhat  raised  above  the  thallus.  Disk  black.  Spores 
oblong,  colorless,  indistinctly  once  to  thrice  septate, 
bearing  oil-droplets,  13/x  X  5/i,. 

This  lichen  is  also  known  as  Collema  nigrum.  It 
forms  inky-black  stains  upon  the  rock  on  which  it 
grows. 

2.  Lecothecium  corallinoides.  Thallus  crustose  to 
minutely  scaly,  scales  ascending,  dark-brown.  Apo- 
thecia sessile,  somewhat  immersed.  Disk  flattened, 
dark-brown.     Spores  few,  elliptical,  14/x  X  '^/w,. 

This   species    is    generally  described   as    Pannaria 

microphyllum. 

3.   Lichina. 

Thallus  crustose,  minute,  branching,  dark,  some- 
what resembling  that  of  Ephehe,  but  differs  in  that  the 
fungal  symbiont  forms  the  greater  bulk  of  the  struct- 
ure and  the  protective  tissue.  The  algse  are  Rivularia 
nitida,  hence  blue-green  and  in  chains.  No  cortical  tis- 
sue is  present. 

The  apothecia  are  small,  terminal,  globose,  appear- 
ing as  small  nodular  enlargements  of  the  ends  of  some 
branches.  They  are  dark.  Spores  are  simple,  ellipti- 
cal, colorless.     The  hypothecium  is  colorless. 

Only  a  few  species  are  known,  they  occur  upon 
rock  in  moist  places  and  are  found  in  the  tropics 
as  well  AS  in  the  far  north. 

1.  Lichina  conjinis.  Thallus  minute,  branching, 
lobes  rigid  and  erect,  dark.  Apothecia  terminal, 
globose,  dark.     Spores  colorless,  simple,  elliptical. 


GENERA    AND    SPECIES. 


189 


^.    Omphalaria. 

Thallus  small,  fruticose,  lobes  flattened,  dark.  The 
apothecia  are  terminal,  nearly  globose,  dark.  In  fact 
the  genus  closely  resembles  Lichina.  The  algal  sym- 
biont  varies,  however.  Upon  close  examination  it 
will  be  found  that  the  predominating  alga  is  single 
celled,  with  a  thick,  colorless,  gelatinous  covering,  and 
is  evidently  Glceocapsa polydermatica.  Nostoc  is,  how- 
ever, also  present,  at  least  in  most  specimens. 

The  spores  are  simple,  colorless,  elliptical ;  again 
they  are  evidently  septate.  They  occur  upon  rock  in 
the  temperate  and  arctic  zones.     The  genus  requires 

further  study. 

1.  Omphalaria  umhella,  Thallus  small,  attached 
by  an  umbilicus,  branching,  lobes  flattened  and  crenu- 
late,  dark  to  nearly  black.  Apothecia  terminal, 
globose  to  discoid.  Disk  brown.  Spores  simple, 
colorless,  elliptical,  18/w,  X  7.5^. 

5.    Polychidium. 

Thallus  small,  fruticose,  branching,  lobes  cylindrical, 
dark.  There  is  a  cortical  tissue  present,  thus  distin- 
guishing the  genus  from  the  genera  already  described. 
The  algfe  are  evidently  Rivularia  or  modified  Nostoc. 
The  general  gross  characters  of  the  thallus  resemble 
those  of  Ephehe. 

The  apothecia  are  small,  discoid,  and  sessile  upon 
the  basal  portion  of  the  thallus.  Disk  brown  and 
hypothecium  colorless.  The  spores  are  oblong,  ellipti- 
cal or  spindle-shaped  to  somewhat  curved,  two-celled, 
colorless.     This   genus    also   requires    further   careful 


190  GUIDE    TO    THE    STUDY    OF    LICHENS. 

study;  at  present  it  is  generally  included  under  Lepto- 
gium. 

1,  Polychidium  muscicolum.  Tliallus  small,  fruti- 
cose,  much  branched,  lobes  cylindrical,  dark  to  olive- 
black.  Apothecia  medium,  discoid  upon  the  older 
basal  branches.  Disk  flattened  to  concave,  brown. 
Spores  typical  of  the  genus,  25;a  X  8/x. 

This  lichen  is  found  growing  over  moss,  on  rocks, 
and  occurs  at  great  altitudes.  It  frequently  occurs  on 
high  rocks  facing  the  ocean. 

6.  Heppia. 

Thallus  of  medium  size,  foliose,-  monophyllous, 
closely  adnate  to  the  substratum ;  margin  more  or  less 
lobed ;  brown  color,  becoming  quite  dark  with  age. 
Rhizoids  numerous.  The  algse  are  perhaps  a  species 
of  Scytonema. 

The  apothecia  are  comparatively  large,  innate  in 
concave  depressions  of  the  thallus,  a  characteristic  not 
occurring  in  any  other  lichen-genus.  The  hypothecium 
is  colorless.  Disk  reddish-brown.  Spores  are  colorless, 
simple,  thin-walled  with  granular  contents,  and  vari- 
able in  size  and  form. 

1.  Heppia  Despreuxii.  Thallus  foliose,  monophyl- 
lous, margin  lobate,  closely  adherent  to  substratum, 
dark.  Apothecia  typical  of  the  genus.  Spores  typical, 
22/t  X  9/^. 

There  is  perhaps  only  one  authentic  species  in  exist- 
ence. The  European  specimens  labelled  H.  urceolata 
and  H.  adglutinata  are  in  all  respects  similar.  H. 
Despreuxii  is  southern  and  occurs  upon  sandy  soil. 


GENERA    AND    SPECIES.  191 


7.  Psoroma. 


Thallus  foliose,  branching,  lying  flat  over  substra- 
tum. The  alga3  are  Protococcus.  It  is  perhaps  prob- 
able that  this  genus  is  phylogenetically  derived  from 
Pannaria  which  genus  it  resembles  in  all  but  the  algal 
characters. 

Apothecia  discoid,  margin  irregular.  Disk  reddish- 
brown.     Spores  colorless,  simple,  spindle-shaped. 

1.  Psoroma  hypnorum.  Thallus  consisting  of  as- 
cending scales  which  are  more  or  less  lobed,  reddish- 
brown.  Apothecia  medium  to  large,  margin  crenulate 
and  bearing  thalloid  outgrowths.  Disk  reddish-brown. 
Spores  typical,  13.5/x  X  9/w- 

2.  Psoroma  stellata.  Thallus  of  imbricate,  many 
cleft,  ascending  lobes  with  crenate  margin,  pale  brown 
above  ;  whitish  beneath  with  numerous  rhizoids.  Apo- 
thecia few,  small  to  medium,  sessile.  Disk  convex, 
pale  brown  to  reddish-brown.     Spores  rare,  not  seen. 

8.  Pannaria. 

Thallus  foliose,  lobed  and  usually  of  a  reddish-brown 
color  above,  pale  beneath.  The  lower  forms,  however, 
approach  the  crustose  type.  The  alga?  are  blue-green 
in  color,  and  occur  in  groups  (^Poly coccus punctiformis). 
The  apothecia  are  usually  quite  small,  discoid,  sessile. 
Disk  flattened,  with  margin  somewhat  raised,  reddish- 
brown  ;  hypothecium  colorless.  The  spores  resemble 
those  of  the  preceding  genus. 

The  genus  is  somewhat  southern  in  its  range  ;  the 
species  occur  upon  moss,  soil,  rock  and  trees.    At  present 


192  GUIDE    TO    THE    STUDY    OF    LICHENS. 

considerable  confusion  exists  as  to  the  limitations  of 
the  genus. 

i.  Pannaria  hrunnea.  Thallus  from  coarsely  warty 
to  minutely  foliose,  tawny-brown.  Apothecia  medium, 
margin  rugose,  warty.  Disk  flattened  to  concave,  red- 
dish-brown. Spores  simple,  colorless,  granular,  ends 
pointed,  18/x  X  9/><" 

2.  Pannaria  lepidiota.  Thallus  of  small  closely 
adnate  or  sometimes  ascending  lobes,  branching,  warty 
and  more  or  less  crenate,  brown  to  dark-brown.  Apo- 
thecia small,  margin  crenate.  Disk  flattened,  reddish- 
brown  to  dark-brown.  Spores  simple  or  apparently  two- 
celled,  contents  granular,  oblong  elliptical,  15/x  X  6/x,. 

3.  Pannaria  leucosticta.  Thallus  foliose,  adnate, 
lobed,  much  divided  and  more  or  less  ascending,  mar- 
gin whitish  ;  greenish-gray  above,  dirty  gray  beneath. 
Apothecia  small,  margin  crenulate.  Disk  convex, 
reddish-brown.  Spores  simple,  colorless,  enclosed  by 
a  spindle-shaped  gelatinous  mass,  12/x  X  6/i. 

4-  Pannaria  luridum.  Thallus  quite  large,  lobed, 
brown  to  bluish-brown  above  ;  light-gray  to  bluish-gray 
beneath,  with  numerous  dark  rhizoids.  Apothecia 
small,  margin  almost  entire.  Disk  convex,  pale  chest- 
nut to  dark.  Spores  simple,  colorless,  spheroidal  to 
spindle-shaped,  spore-wall  warty,  10.5/x  X  8/x. 

This  lichen  is  often  classed  as  Physma  luridum. 

5.  Pannaria  ruhiginosa.  Thallus  much  branched, 
margin  faintly  white ;  brown  above,  dark  beneath. 
Apothecia  rather  small,  margin  crenate.  Disk  con- 
vex, reddish-brown.  Spores  spheroidal,  spore-wall 
comparatively  thick,  13/x  X  10/** 


GENERA    AND    SPECIES.  193 

6.  Pannaria  molybdcea.  Thallus  large,  mostly  en- 
tire, margin  lobed,  gray  to  bluish-gray  •  light-gray 
to  yellowish  beneath  with  gray  rhizoids.  Apo- 
thecia  variable  in  size.  Disk  convex,  irregular  in 
outline,  pale  chestnut  changing  to  nearly  black. 
Spores  simple  or  indistinctly  two-celled,  colorless, 
spindle-shaped,  11^  X  4.5/x. 

9.  Peltigera. 

Thallus  large,  lobes  rounded  and  large.  As  a  rule 
the  thallus  is  quite  thick  and  rigid  but  not  brittle. 
Color  above  is  generally  bright  blue-green,  which 
promptly  changes  to  brown  on  drying ;  the  lower  sur- 
face is  light-brown  and  bears  large  simple  and  branch- 
ing rhizoids. 

Upon  examining  a  vertical  section  of  the  thallus  it 
is  found  that  no  lower  cortical  tissue  is  present,  as  one 
would  expect  in  so  large  a  plant.  The  algae  are  blue- 
green,  as  in  Pannaria  {Poly coccus  punctiformis) . 

The  apothecia  are  quite  large  and  are  innate  upon 
the  upper  margin  or  terminal  upon  special  lobes.  In 
outline  the  apothecia  are  orbicular  to  somewhat  oval. 
The  spores  are  acicular,  colorless,  three  to  five-septate, 
usually  somewhat  curved. 

The  range  of  the  species  is  northern,  though  some 
occur  south.  They  grow  upon  rock,  more  commonly 
upon  soil  in  forest  lands  among  mosses,  also  at  the 
basal  portions  of  tree-trunks.  They  do  not  thrive  in 
open,  exposed  places. 

1.  Peltigera  apthosa.  Thallus  large,  lobes  broad, 
upper  surface  sprinkled  with  flattened    brown  warts, 


194  GUIDE    TO    THE    STUDY    OF    LICHENS. 

bluish-green  above ;  pale  and  reticulate  beneath,  with 
comparatively  few  large  rhizoids.  Apothecia  medium, 
marginal  on  large  lobes.  Disk  reddish-brown.  Spores 
typical,  65/A  X  6/a. 

Some  of  the  uses  of  this  lichen  have  already  been 
referred  to  elsewhere.  According  to  Willemet,  it  was 
an  excellent  vermifuge  when  given  in  doses  of  twelve 
grains,  evening  and  morning,  during  six  or  eight  days. 
It  was  also  said  to  possess  emetic  properties. 

2.  Peltigera  canina.  Thallus  large,  lobes  large, 
rounded,  greenish-gray  and  smooth  above ;  beneath 
paler  and  reticulate  with  whitish  rhizoids.  Apothecia 
medium  to  large,  marginal.  Disk  reddish-brown. 
Spores  acicular,  three  to  five-septate,  65/a  X^/x. 

This  is  the  lichen  which  obtained  such  renown  as  a 
remedy  for  the  cure  of  hydrophobia.  It  was  also  con- 
sidered to  have  diuretic  properties. 

3.  Peltigera  polydactyla.  Thallus  large,  smooth 
above,  greenish  to  brown  ;  beneath  reticulate  with  com- 
paratively few  rhizoids.  Apothecia  medium,  terminal 
on  narrowed  thallus-lobes.     Spores  typical. 

10.  Solorina. 

The  thallus  is  quite  large,  foliose,  rigid,  and  re- 
sembles the  thallus  of  the  foregoing  in  that  the  lower 
cortical  layer  is  wanting.  It  is  loosely  attached  to 
the  substratum  by  long  rhizoids.  The  upper  surface 
is  smooth  and  brown  in  color ;  the  lower  surface  is 
light-brown  to  brick-red  {S.  croced).  Two  forms  of 
algae  are  present;  one  bright-green  {Dactylococcus), 
the  other  blue-green  i^Poly coccus). 


GENERA    AND    SPECIES.  195 

The  apothecia  resemble  those  of  Peltigera  ;  the  disk 
is  brown  to  dark-brown.  The  spores  are  elliptical, 
two-celled  and  brown  in  color. 

The  Solorinas  are  northern  in  their  range,  occurring 
among  moss,  upon  rock  and  soil. 

1.  Solorina  crocea.  Thallus  rather  small,  not  dis- 
tinctly branching,  closely  adnate  to  substratum  ;  brown 
above,  orange-red  beneath,  with  darker  veins.  Apo- 
thecia medium  to  large.  Disk  reddish-brown.  Spores 
typical  of  genus,  50/x,  X  20/a. 

2.  Solorina  saccata.  Thallus  thinner  than  in  S. 
croceay  paler.  Apothecia  medium,  in  depressions  of 
the  thallus.     Spores  typical,  50/tx  X  20/x. 

11.  Nephromium. 

The  thallus  of  Nephromium  has  a  distinct,  well- 
developed  Ibwer  cortical  layer,  from  the  lower  surface 
of  which  extend  long  rhizoids.  In  other  respects  the 
thallus  resembles  that  of  the  Peltigeras.  (The  algae 
are  blue-green  and  occur  in  colonies  as  in  Peltigera.') 

The  apothecia  are  more  or  less  oval  or  kidney-shaped 
and  are  marginal  upon  the  lower  surface  of  upturned 
lobes,  a  character  not  found  in  any  other  lichen-group. 
The  disk  is  reddish-brown.  The  spores  vary  from 
nearly  acicular  to  oval,  usually  four-celled  and  brown. 

Some  species  have  bright-green  algte  (Protococcus), 
and  should  be  classed  with  another  genus  {Nephroma). 

The  species  are  northern  in  their  range,  and  occur 
upon  rock  and  tree-trunks  in  shaded  places. 

i.  Nephromium*l(Evigatum.  Tliallus  medium,  lobes 
rather  small,  rounded,  undulate,  brown  above;  paler 


196  GUIDE    TO    TFIE    STUDY    OP    LICHENS. 

beneath  and  somewhat  reticulate.  Apothecia  medium. 
Disk  reddish-brown.  Spores  fusiform-elliptical,  brown, 
20/x  X  6/i. 

2.  Nephromium  Lusitanicum.  Thallus  medium, 
lobes  deeply  cut,  sinnate,  margin  crenate,  dark-brown ; 
the  interior  appears  yellowish.  Apothecia  and  spores 
mufeh  as  in  N.  Icevigatum. 

3.  Nephromium  Helveticum.  Thallus  medium,  lobes 
rather  narrowed,  undulate,  smooth  above  gray  to 
tawny  ;  dark  beneath.  Apothecia  medium.  Disk  dark. 
Spores  as  in  N.  Icevigatum. 

4'  Nephromium  tomentosum.  Thallus  large,  lobes 
rounded,  undulate  and  crenate  margin,  gray  to  reddish- 
brown  above  ;  paler  beneath.  Apothecia  medium.  Disk 
reddish-brown.     Spores  much  as  in  N  Icevigatum. 

12.  Stictina.  » 

Most  authors  combine  Stictina  with  Sticta,  but  ow- 
ing to  distinct  algal  differences  we  have  kept  them 
separate. 

The  thallus  is  large,  lobed,  medium  in  thickness  and 
brittleness.  It  reminds  one  somewhat  of  Parmelia 
and  Physcia.  The  lobes  usually  lie  flat  upon  the  sub- 
stratum and  are  rather  loosely  attached  by  rhizoids. 
Color  is  generally  dark-brown  tinged  with  bluish-green. 
The  algae  are  blue-green  and  occur  in  colonies  (as  in 
Pannaria  and  Peltigerd). 

There  is  a  morphological  character  by  means  of 
which  one  may  recognize  most  of  the  representa- 
tives of  Stictina  as  well  as  Sticta,  and  that  is  the 
occurrence  of  cyphellae  upon  the  lower  surface.    (See 


GENERA    AND    SPECIES.  197 

Cyphella.)  There  are,  however,  exceptions  (Sticta 
amplissima,  S.  pulmonaria,  and  several  others). 

The  apothecia  are  rather  small,  discoid,  sessile. 
Disk  slightly  concave,  flattened  to  slightly  convex. 
Spores  colorless,  oblong  to  acicular,  four-celled. 

The  species  are  southern  in  their  range,  they  occur 
upon  trees  and  rocks. 

1.  Stictina  tomentosa.  Thai! us  medium,  deeply 
lobed,  pitted  above  and  bluish-brown,  paler  beneath, 
with  white  cyphella3  and  rhizoids.  Apothecia  medium, 
scattered,  sometimes  marginal.  Disk  reddish-brown 
to  dark.     Spores  typical,  4o/a  X  10/u,. 

2.  Stictina  quercizans.  Thallus  rather  large,  lobes 
rounded  and  somewhat  imbricate,  sinuate  and  crenate, 
dark-brown  above;  rhizoids  and  white  cyphella?  be- 
neath. Apothecia  rare,  medium.  Disk  dark-brown. 
Spores  typical. 

There  are  a  considerable  number  of  species,  but 
none  have  marked  distinctive  characters.  The  ama- 
teur will  perhaps  be  satisfied  to  give  the  plants  col- 
lected their  generic  position.  In  fact,  by  doing  so 
he  will  do  no  small  part  toward  defining  the  limitations 
of  the  two  genera.  Further  study  may  show  that  the 
Stictinas  and  Stictas  devoid  of  cyphellce  do  not  belong 

here. 

13.    Sticta. 

Thallus  in  all  respects  similar  to  that  of  Stictina. 
Color  less  dark  and  less  tinged  with  blue,  owing  to 
the  fact  that  the  algaj  are  briglit-green  {Profococ- 
cus). 

The  apothecial  and  spore-characters  are  similar. 


198  GUIDE    TO    THE    STUDY    OF    LICHENS. 

Considerable  variation  has  been  noted  in  the  apo- 
thecial  characters  of  some  Stictas  which  leads  to  the 
conclusion  that  some  of  the  apothecia  may  be  the  fruc- 
tification of  a  fungal  parasite  closely  related  to  Arthonia. 
Particularly  has  this  been  observed  in  S.  pulmonaria. 
Further  careful  research  is  necessary  to  determine  the 
parasites  living  upon  lichens.  Let  us  hope  that  some 
of  the  amateurs  for  whom  this  book  is  written  may 
make  observations  and  studies  which  will  aid  in  clear- 
ing up  some  of  these  mysteries. 

The  Stictas  are  less  distinctively  southern  in  their 
range.  The  change  in  algal  symbiont  may  have  en- 
abled the  plants  to  thrive  in  a  colder  climate.  They 
occur  upon  rocks  and  trees. 

1.  Sticta  amplissima.  Thallus  large,  parmelioid, 
rather  thin  and  papery,  lobed,  grayish-green  and 
smooth  above ;  brown  beneath,  with  rhizoids  but  no 
cyphellae.  Apothecia  rather  large,  numerous.  Disk 
chestnut-brown.  Spores  colorless,  long,  slender,  some- 
what curved,  indistinctly  septate,  46/x  X  6/x. 

2.  Sticta  pulmonaria.  Thallus  large,  lobes  long, 
upper  surface  divided  into  concave  areas,  ridges  and 
margin  lined  with  soralia,  dirty  brown  tinged  with 
bluish-green ;  lower  surface  of  convex  areas  light- 
brown,  no  cyphellae.  Apothecia  few,  medium.  Disk 
reddish-brown  to  dark.  Spores  very  closely  resemble 
those  of  Arthonia,  18/x  X  5.5/x. 

This  lichen  quite  generally  occurs  at  the  base  ot 
trees  (weather-side)  at  high  altitudes.  It  is  usually 
isolated,  and  the  entire  plant  has  the  appearance  of 
being  decrepit  and  old,  so  that  upon  seeing  it  for  the 


I'LATK  II.  Folinst' Types,  tliallus  nearly  I'liiin-.  \,  Sticta 
jiuliitoHKrid.  tr.iiii  Mt.  Tanialpais,  .Marin  ("it.,  ("alifornia. 
.'»,  i'liiliiliairia  jtustulata,  from  California  Aeadeuiy  of 
Science. 


GENERA    AND    SPECIES.  199 

first  time  one  is  likely  to  pass  it  by  hoping  to  find  a 
"better"  specimen. 

"  This  lichen  was  at  one  time  much  prized  as  a 
remedial  agent  and  in  the  dyeing  industry.  Its  specific 
name  as  well  as  its  familiar  desis^nation  'luniks  of  oak' 
or  *  tree  lungwort '  is  due  either  to  its  efficacy,  real  or 
supposed,  in  pulmonary  affections,  as  a  nutrient,  de- 
mtflcent  or  tonic;  or  from  a  fancied  resemblance  be- 
tween the  reticulate  character  of  the  thallus  and  the 
mesh-like  structure  of  lungs.  The  Swedish  peasantry 
were  wont  to  employ  it  in  epidemic  catarrh  of  cattle, 
especially  of  sheep ;  and  in  Germany,  probably  for 
similar  purposes,  it  was  given  to  cattle  mixed  with 
salt."  —  Lindsay. 


Library 


LICHENES  IMPERFECTI   OR  FALSE  LICHENS. 

Formerly  various  lichens  and  parts  of  lichens  were 
classed  as  Pseudolichens  or  Lichenes  imperfecti.  Of 
these  six  generic  groups  were  recognized:  Isidium 
Ach.,  Variolaria  Ach.,  Lepra  Hall.,  Pulveraria  Ach., 
Spilonema  Ach.,  Pyrenothea  Fr.  Isidium  included 
the  peculiar  warty  and  isidioid  outgrowths  quite  fre- 
quent on  the  upper  surface  of  foliose  thalli ;  it  also 
comprised  various  sterile  warty  crustose  lichens.  Un- 
der Variolaria  were  included  sterile  forms  of  Pertusa- 
ria  communis,  P.  lactea,  besides  other  sterile  crustose 
lichens  of  a  gray  or  whitish  color,  especially  those 
bearing  numerous  soredia.  Lepra  included  the  pseudo- 
lichen  L.  viridis  as  well  as  sterile  forms  of  Placodium 
and  perhaps  Rinodina.  Under  Pulveraria  were  evi- 
dently included  incipient  primary  thalli  of  Cladonia 
as  well  as  sterile  forms  of  Calicium,  etc.  The  char- 
acters of  Spilonema  are  very  uncertain,  referring,  per- 
haps, to  sterile  forms  of  Graphis,  Arthonia,  etc.  The 
term  Pyrenothea  referred,  no  doubt,  to  low  forms  of 
lichens  (perhaps  old,  dying  plants)  bearing  numerous 
8permagonia,  pycnidia,  or  perhaps  parasitic  fungi. 


THE    CONTINENTAL    RANGE    OF    THE    MORE  IM- 
PORTANT LICHEN  GENERA  OCCURRING 
IN  THE  UNITED   STATES. 

The  following  table  gives  the  general  continental 
range  of  the  lichen-genera  represented  in  the  United 
States.  Some  of  the  genera  are  not  sufficiently  known 
to  indicate  their  true  range;  such  are  marked  with 
an  *.  Those  given  under  *'  U.  S."  are  perhaps  about 
uniformly  distributed  in  the  United  States. 


Northern 

Southern 

Eastern 

Western 

U.S. 

[ros 
Sphseropho- 

Pilophoron 
Stereocaulon 
Cladoiiia 
Thamnolia 

Biatorella* 
Bilimbia* 

Buellia 

Catillaria* 

Megalospora* 

Gyrophora 
Umbilicaria 

BsBomyces 

Bacidia 
Lopadinm 

Caliciacex 
Mycocalici- 

[um* 

Cyphelium 
Cladoniaceee 

Lecideacese 
Graphidacese 

Coniocybe* 
Calicium 
Cyphelium 
Acolium 

Biatorella* 
Biatorina* 
Biatora 
Bilimbia 

Lecidea* 

Celidiopsis* 

Buelliopsis* 

Gyaleota 
Psora 

RANGE  OF  LICHENS  IN  THE  INITED   STATES.       203 


Northern         Soatbern 

Eastern 

Western 

U.S. 

Hazslinskya* 

Opegrapha 
Graphis 
Xylographa 
Arthonia 
Mycoporura 
Arthotheli- 
[um 

Placodiuin 
Pyxine 

Physciacess 

Rinodina 
Placodium 

Hazslinskya 

Rinodina 

Pyxine* 
Physcia 

Physcia 

Theloschistes 

Parmeliacese 

Urceolaria 

" 

Haematomma 

Lecanora 

[dera 
Speerschnei- 

[dera 
Speerschnei- 

Acarospora 
Parraelia 

Cetraria 

Ramalina 

Evernia 
Ramalina 

Alectoria 

Bryopogon 

[um 
Trypetheli- 
Pyrenuia 

Thelotrema 
Gyros  torn  um 
Verrucaria* 

[cex 
Verrucaria. 

1 

Usnea 

Conotrema 
Verrucaria 

Pertusaria 

Dermatocar- 

Pertusaria 

[pon 

Collemaceae 
Pannariacese 

Hydrothyria* 

Endocarpon 

Collenia 
Leptogi  um 
Maliotiura 
Hydroihyria* 

Lecothecium 

Ephebe 
Lecothecium 

Omphalaria 
Polychidium 

Licliina 
Omphalaria 

Psoroma* 

Eleppia 
Pannaria 

Solorina 

Peltigera 

Nephron)  ium 

Stictina 

Sticta               J 

sticta               i 

Sticta 

LIST  OF    LICHENS    OCCURRING    IN    THE    UNITED 
STATES. 

This  list  is  by  no  means  complete.  It  is,  in  fact,  at 
present  impossible  to  give  the  exact  number  of  species 
occurring  within  the  territory  indicated.  Willey  be- 
lieves that  ultimately  one  thousand  species  will  be 
found.  No  authentic  list  can  be  compiled  until  the 
existing  species  have  been  carefully  determined.  It  is 
very  probable  that  a  considerable  number  of  lichens 
have  been  described  as  distinct  species  which  are  in 
reality  one  and  the  same  species  ;  particularly  is  this 
true  of  the  lower  forms. 

The  list  gives  some  idea  of  tho  number  of  species 
occurring  in  the  various  genera,  and  will  be  found  of 
great  value  to  those  who  wish  to  make  exchanges  or 
who  wish  to  build  up  a  fairly  complete  lichen-herba- 
rium. 

The  families  are  given  in  their  natural  order,  while 
the  genera  and  species  are  given  in  alphabetical  order. 
This  arrangement  in  alphabetical  order  is  simply  for 
convenience  of  reference.  The  list  gives  about  1,250 
species  and  varieties ;  of  these,  no  doubt  a  consider- 
able number  are  synonyms.  Furthermore,  there  are 
a  few  doubtful  genera  and  species  which  have  been  en- 
tirely omitted.  It  is  highly  probable  that  there  are 
not  more  than  1,200  authentic  species  and  varieties  of 
lichens  in  the  United  States. 


CALICIACE^. CLADONIACE^. 


205 


I.  Caliclaceee 

J.  Acolium 

Bolanderi 

Californicura 

Carolinianum 

chloroconium 

Hawaiiense 

Javanicum 

leucampyx 

stigonela 

Sti.  Jacobi 

tympanella 

viridula 

S.  Acrocyphus 

sphasrophoroides 

S.  Calicium 

albo-nigrum 

brunneolum 

byssaceum 

chrysocephalum 

citrinum 

Curtisii 

curtum 

disseminatum 

eusporum 

facultatum 

fucipes 

hyperellum 

lenticulare 

leucochlorum 

leucopodum 

melanophaeum 

microcephalum 

parietinum 

phaeocephalum 

polyporajum 


praecedens 
puUatulum 
quercinurn 
Ravenelii 
roscidum 
subcinereum 
subtile 
trachelium 
trichiale 
tubaeforme 
turbinatum 
4-  Coniocybe. 
albella 
furfuracea 
pallida 

5.  Mi/cocalicium 

Curtisii 
fucipes 

6.  Pyrgillus 

Araericanus 

7.  Sphcerophorus 

compressus 
coralloides 
fragilis 

8.  Sphinctrina 

anglica 

leucopoda 

turbinata 

II.  Cladonlaces 

1.  Bccomyces 
absolutus 
ffiruginosa 
byssoides 
fungoides 
placopliyllus 
roseus 


206 


CLADONIACEiE. 


S.  Cladonia 
alcicomis 
amaurocraea 
bellidiflora 
Boryi 
botrytis 
caespiticia 
cariosa 
carneola 

cyanipes 
cenotea 

furcellata 
ceratophylla 
cornucopioides 
cornuta 
cristatella 

ramosa 
dactylota 
decorticata 
deformis 
degenerans 
delicata 
digitata 
Dilleniana 
endiviafolia* 
fimbriata 

tubseformis 

radiata 
Floerkeana 
furcata 

a.  crispata 

h.  ramosa 

c.  subulata 

d.  pungens 

e.  racemosa 
gracilenta 
gracilis 


a.  verticilata 
*  cervicornis 

**  sy  mphy  carpia 

b.  hybrida 

c.  elongata 
hypoxantha 
leporina 
macilenta 
mitrula 
papillaria 
pulcliella 
pyxidata 

b.  pocillum 
rangiferina 

b.  sylvatica 

c.  alpestris 
Ravenelii 
santensis 
sympliycarpa 

6.  epiphylla 
squamosa 
turgida 

b.  conspicua 
uncialis 

3.  Endogene 
informis 
4-  Pilophoron 
cereolus 
a.  fibula 
6.   Hallii 

c.  aucicularis 

d.  robustus 
5.  Siphula 

ceratites 
dactyliza 
Pickeringii 
Ramalinoides 


CLADONIACEiE.  —  LECIDIACK^E. 


20: 


cornuta 
simplex 
subtabularis 
6.  Stcreocdulon 
albicans 
alpestre 
clavipes 
coiidensatum 
coralloides 
(lemulatum 
maderense 
nahodes 
paschale 
piliatum 
pilophoroides 
proxinum 
ramulosum 

vimineum 
Wriffhtii 
tomentosuin 

b.  Alpinum 
7.  Thamnolia 

vermicularis 

a.  subuliformit 

b.  taurica 

III.  Lecidiacese 

1.   Bacidia 

alborussula 

atrogrisea 

atrosanguinea 

Beckliausii 

chloraniha 

cUlorosticta 

effusa 

b.  arcontina 
fusco-rubella 


incompta 
inundata 
rnedialis 
raicTophyllina 
millegrana 
nmscoruni 
rubella 
rufescens 
Schweinitzii 
stigniatella 
subabbrevians 
suffusa 
unibrian 
2.  B I  at  or a 
aenea 

anthrocophila 
apochroeiza 
atro-rufa 
aurigera 
carnulenta 
cinnabarina 
circumflexa 

coarotata 

b.  Brugeriana 

cuprea 

denotata 

Uiapensia) 

ementiens 

exigiia 

flavido-liviens 

flexuosa 

furfuracca 

furfurosa 

fuscescens 

glebulosa 

granulosa 

hypouiela 


208 


LECIDIACE^. 


inspersabilis 

internectans 

Konyamensis 

leucophaea 

lucida 

mutabilis 

myriocarpoides 

Nylanderi 

oxyspora 

parvifolia 

b.  subgranuloea 

c.  corallina 
peliaspis 
peliaspistes 
punctella 
pycnotheliza 
quernea 
rivulosa 

b.  mollis 
rubidula 
rufo-fusca 
rufo-fuscella 
russula 

sanguineo-atra 
spurococca 
subdeusta 
Torneonsis 
turgidula 
uliginosa 
varians 
vernalis 
viridescens 
b.  gelatinosa 
S.  BiatoreUa 
campestris 
cyphalea 
fossarum 


geophana 
ilicis 

moriformis 
resinae 
4-  Biatorina 

atro-purpurea 

curaulata 

cyrtella 

denigrata 

erysibe 

expallescens 

glauconigrans 

globulosa 

gyalizella 

Heerii 

lutea 

micrococca 

mixta 

pineti 

prasina 
5.  Bilimbia 

allinita 

artyta 

caudata 

cupreo-rosella 

declinis 

Friesiana 

hyaliniza 

hypnophila 

leucoblephara 

melaena 

milliaria 

Nagelii 

obscurata 

pallidella 

parasitula 

sphaeroides 


LECIDIACE^. 


209 


suballinita 

subfuscula 

trachona 

tricholoma 

trisepta 

verecunda 
6.  Buellia 

Africana 

albo-atra 

b.  saxicola 
allothallina 
alpicola 
amphidextra 
atro-albescens 
attendenda 
badia 
badio-atra 
bolacina 
Bolanderi 
calcarea 
Caloosensis 
catasema 
Catawbensis 
coUudens 
coracina 
decinerascens 
destitula 
dialyta 
Eliza 
epigea 
geographica 

b.  lecanorina 
glauconiaria 
glaucomarioides 
halonia 
ignobile 
infernula 


inquilina 

Japonica 

lactea 

lepidastra 

leptocline 

leucosepha 

meiosperma 

myriocarpa 

b.  polyspora 
minimula 
ochrodela 
Oderi 
oidalea 
pappillata 
parasenia 
parasitica 
parasitula 
parmeliarura 
pertusaricola 
petraea 

b.  grandis 

c.  Montagnaei 

d.  albinae 
praebadia 
pulchella 
pullata 
Ravenelii 
retrovertens 
Rittokensis 
saxatilis 
scabrosa 
Schaereri 
Semitensis 
seinotula 
Smithii 
spuria 
squamulata 


210 


0                                             LECIDIACE^. 

stellulata 

vellea 

stigmsea 

12.  Lecidea 

trypethelia 

acclinis 

turgescens 

aglam 

urceolata 

aglasida 

vilis 

albocoerulescens 

7.  BuelUopsis 

h.  flaA'ocoerulescens 

platycarpa 

alpestris 

8.   Cattillaria 

amylacea 

grossum 

arctica 

9.   Celidiopsis 

b.  pallida 

vernicoma 

Armeniaca 

10.   Gyalecta 

aromatica 

carneo-luteola 

assimilata 

cupularis 

atrobrunnea 

faxicola 

auriculata 

riotovii 

diducens 

Friesii 

Brandegeei 

geoica 

borealis 

*  trivialis 

brachyspora 

lutea 

Candida 

nana 

caudata 

pineti 

cceruleonigricans 

rhexoblephara 

conferenda 

Valenqueliana 

confluens 

11.   Gyrophora 

contigua 

anthracina 

h.  hydrophila 

h.  reticulata 

crassipes 

Dillenii 

cruciarea 

erosa 

crytidia 

flocculosa 

cumulata 

hirsuta 

dendroclinis 

hyperborea 

dispecta 

Miihlenbergii 

elata 

polyphylla 

enteroleuca 

proboscidea 

h.   theioplaca 

6.  arctica 

c.  equata 

LECIDIACEiE. 


211 


d.  muscorum 
€.   achrista 
/.    flavida 
g.   ambigua 

epiiodiza 

erratica 

flavovirescens 

fusco-atra 

fusco-cinerea 

glaucospora 

granosa 

insularis 

lapicida 

Laurentiana 

limosa 

lugubrior 

lugubris 

lygotropa 

mamillana 

Manni 

massata 

melanoheima 

melapsepha 

monticola 

micytho 

neglecta 

pallida 

panocola 

paraphana 

parasitica 

paupercula 

planetica 

platy  carpa 

polycarpa 

Pringlei 

pruniosa 

psephota 


pycnocarpa 

Rhajtica 

ruginosa 

scrobiculata 

Simodensis 

sporostatia 

apeiorea 

squalida 

subliraosa 

subtristisinscula 

sylvicola 

tenebrosa 

tessellata 

tessellina 

ultima 

variegata 

viiellinaria 

vorticosa 
13.  Lopadium 

pezizoideum 

vulpinum 
14-  Afegalospora 

porphyrites 

sanguinaria 
15.  Psora 

anthracophila 

atro-rufa 

caulophylla 

crenata 

decipiens 

Friesii 

glob  if era 

b.  rubiformis 

icteria 

luridella 

ostreata 

Petri 


212 


LECIDIACKiE. 


GRAPHIDACE^. 


rufo-nigra 

Russellii 

scotopholis 

16.  Sporastatia 

morio 
6.  coracina 

17.  Toninia 

aclinis 

caudata 

flavovirescens 

granosa 

massata 

ruginosa 

squalida 

18.  Umbillcaria 

Pennsylvanica 
pustulata 
h.  papulosa 

IV.  Qraphidacese 

1.  Arthonia 

abrothallina 
albofuscescens 
astericus 
•astroidea 

swartzoidea 
atrata 
carneo-rufa 
caudata 
chiodectella 
cinnabarina 
conturbata 
cupressina 
cyrtodes 
diffusa 
dispersa  , 
Eekfeldtii 


epipastoides 

erubescens 

erupta 

excedens 

exilis 

fissurinea 

Floridana 

glaucescena 

glebosa 

gregaria 

gregarina 

hamamelidis 

Hibernica 

impallens 

impolita 

chiodectiodes 
incarnata 
lapidicola 
lecideella 
leucastraea 
lurida 
lurido-alba 
mediella 
melaspora 
ochrolutea 
opegraphina 
oxytera 
palmicola 
paralia 

platygraphidea 
platyspeila 
polymorpha 
punctiforrais 
phyrrhula 
phyrrhuliza 
quintaria 
radiata 


(JKAl'HIDACK^:, 


213 


ramulosa 

Kavenelii 

reneformis 

rubella 

saiiguinoa 

subastroidella 

subcyrtodes 

subminutissima 

subniinutula 

subpalliduscula 

subrubella 

taedescens 

tagdiosa 

terigena 

varia 

varians 

velata 

vernans 

violascens 
subcinerascens 

Xylographica 
S.  Arthothelium 

interveniens 

macrotheca 

mesoleuca 

spectabile 
S.  Gli/phis 

Achariana 

labyrintliica 
4'   Graphis 

Afzelii 

assirailis 

Babingtonii 

botryosa 

eolumbina 

conietia 

dendritica 


discurrens 

Dumaslii 

elegans 

erumpens 

eulectra 

Floridana 

glaucoderma 

haematites 

hololeucoides 

hypoleptella 

intricans 

inusta 

leiogrammodes 

leprocarpa 

leucocephola 

leucopepla 

Mosquitensis 

nitida 

nitidella 

nitidesceiM 

oscitans 

patellula 

Pavoniana 

Poitaeoides 

punctiformis 

radiata  ^ 

rigida 

rufula 

scalpturata 

scolecites 

scripta 

linitata 

recta 

serpentina 

varia 
sophistica 
striatula 


214 


^ 

GRAI'HIDACK^. 

PHYSCIACE^. 

subnitidula 

ciliaris 

substriatula 

b.  crinalis 

tricosa 

comosa 

5 

HazUnszkya 

crispa 

demissa 

dilatata 

6. 

Opegrapha 

integrata 

astraea 

erinacea 

atra 

granulifera 

hapalea 

hispida 

Bonplandi 

hypoleuca 

levidensis 

hypomela 

microcyclia 

Leana 

notha 

leucomela 

oalochila 

major 

prosodea 

obscura 

quaternella 

pulverulenta 

riraalis 

b.  leucoleiptes 

tribulodes 

Ravenelii 

varia 

setosa 

viridis 

speciosa 

vulgata 

stellaris 

lithyrga 

6.  aipolia 

7. 

Xylographa 

tribacea 

disseminata 

Wrightii 

hians 

3.  Placodium 

•pegraphella 

aurantiacum 

parallela 

cerinum 
6.  sideritis 

V.  Physciaceae 

c.  pyracea 

1. 

Dimelcena 

cinnabarinum 

oreina 

cirrochroum 

2. 

Physcia 

citrinum 

adglutinata 

cladodes 

aquila 

comptidium 

b.  detonsa 

coralloides 

astroidea 

crenatellum 

ceasia 

elegans 

PHYSCIACK^. 


PARMELIACE^. 


215 


erythranthum 
eupyrmn 
fcrnitrineum 
h.   Pallinii 

c.  discolor 

d.  Wright ii 
ferruginosum 
Floridanum 
fulgens 

b.  bracteatum 
galactophyllum 
Jungerraanniae 
luteorninium 
microphyllum 
murorum 
nivale 
Faumotense 
peliophyllum 
phaeum 
rupestre 
sinapispemum 
spadiceura 
Spraguei 
variabile 

b.  atro-album 
vitellinum 

b.  aurellum 

4.  Pi/xine 

cocoes 

Frostii 

Meissneri 

picta 

sorediata 

5.  Rinodina 

ascocisoana 

aterrima 

Bishoffi 


chrysomelaena 

Conradi 

constans 

flavonigella 

Hallii 

maniillana 

niilliaria 

nimbosa 

ochrotis 

radiata 

sophodcs 

b.  atrocinera 

c.  tephraspis 

d.  confragosa 

e.  exigua 
Thorn  ae 
thysanota 
turfaceae 

6.  roscida 

c.  mniaraea 
6.   Thelochistes 

crysophthalmus 

b.  flavicans 
concolor 

b.  effusa 
flavicans 
lychneus 
parietinus 
polycarpus 
ramulosus 

VI.  Parmeliaceie 

1.  Ahctoria 
Fremontii 
Japonica 

(I.  bicolor 

6.   chalvlti'ifDrmis 


216 


>                                          PARMELIACE^. 

c.  iniplexa 

odontella 

Loxensis 

platyphylla 

nitulifera 

ramulosa 

ochroleuca 

Richardsoma 

a.    rigida 

saepincola 

*  asteina 

b.  chlorophylla 

**  nigrescens 

tristis 

b.    cincinnata 

4'   Conotrema 

c.    sarmentosa 

urceolatum 

£.  Bryopogon 

5.  Evernia 

Oregana 

divaricata 

jubata 

furfuracea 

S.  Cetraria 

b.  cladonia 

aculeata 

prunastri 

aleurites 

trulla 

h.  placardia 

vulpina 

arctica 

6.   Gt/rostomum 

aurescens 

scyphuliferum 

Califomica 

7.  Hcematoma 

chrysantha 

achrophaea 

ciliaris 

clatina 

cucullata 

Hageni 

Fahlunensis 

punicea 

Fendleri 

ventosa 

glauca 

8.  Lecanora 

b.  stenophylla 

acarospora 

Islandica 

b.   pruniosa 

b.  Delisaei 

c.  Clavus 

juniperina 

d.  revertens 

h.  terrestris 

athrocarpa 

c.  pinastri 

atra 

lacunosa 

atriseda 

b.  stenophylla 

Bockii 

madreporiformis 

badia 

nigricans 

calcarea 

nivalis 

b.  contorta 

Oakesiana 

Cenisia 

PARMKLIACKiE. 


217 


cervina 

b.  Tliamnina 
cinerea 

b.  lasvata 

c.  gibbosa 
cupressi 
epulotica 

b.  subpulotica 
frustulosa 
fuscata 

6.  rufescens 
gelida 
glaiicocarpa 

b.  verrucosa 
Haydeni 
lacustris 
lentigera 
miculata 
raolybdina 
niurialis 

a.  saxicola 

b.  Garovaglii 

c.  diffracta 

d.  semitensis 
€.   versicolor 

odora 
pallescens 

b.  rosella 
pallida 

b.  cancriformis 

c.  angulosa 
rubina 

b.  heteromorpha 

c.  opaca 
sordida 
subfusca 

a.  allophana 


b.  hypnoruin 

c.  argentata 

d.  coilocarj)a 

e.  distans 
tartarea 
varia 

b.  polytropa 

c.  intricata 

d.  symmicta 

e.  saepincola 
verrucosa 

b.  mutabilis 
virens 
vitellina 
Willeyi 
xanthophana 
9.  Mi/coporum 

pycnocarpum 
10.  Parmelia 
ambigua 

b.  albescens 

c.  Halli 
aurulenta 
Borreri 

b.  rudecti 

c.  hypomela 
caperata 
centrifuga 
cervicornis 
cetrata 
colpodes 
conspersa 
crinita 
cyclocelis 
encausta 

b.  alpicola 
flavicans 


218 


PARMELIACE^. 


glomulifera 
hypoleuca 
incurva 

Japonica  [icana 

Kamtschadalis  Amer- 
laevigata 
lanata 
lattissima 
leucochlora 
lophyraea 
molliuscula 
olivacea 
*aspidota 

b.  prolixa 

*  pannif  ornis 

c.  soridiata 
perforata 

*  hypotropa 
perlata 
pertusa 
physodes 

b.  obscurata 

c.  enteromorpha 

d.  vittata 
placardia 
revoluta 
saxatilis 

b.  sulcata 

c.  panniformis 

d.  amphalodes 
speciosa 
subrugata 
sulphurata 
stygia 
Texana 
tiliacea 

b.   subleavijijata 


c.  relicina 

d.  sulphurosa 
11.  Pertusaria 

albinea 

ambigens 

bryontha 

coccophora 

colobina 

communis 

concreta 

dactylina 

euglypta 

flavicunda 

globularis 

glomerata 

lactea 

lecanina 

leioplaca 

multipuncta 

panyrga 

pertusa 

pustulata 

rhodocarpa 

velata 

Wulfenii 

12.  Phlyctis 

subtile 

13.  Ramalina  « 

calicaris 
a.  fraxinea 
6.  fastigiata 

c.  canaliculata 

d.  farinaeea 
ceruchis 
complanata 
crinita 
dasypoga 


U- 


15. 


PARMKLIACE^. 

denticulata 

leucastrum 

*canalicularis 

lirelliforme 

honialea 

microcarpum 

leavigata 

monosporum 

linearis 

myrioporum 

Manni 

piluliferum 

Menziesii 

platycarpoides 

poUinarella 

platycarpum 

pollinaria 

postpositum 

polyinorpha 

Ravenelii 

pusilla 

Santense 

b.  geniculata 

simplex 

reticulata 

subtile 

rigida 

Wightii 

Montagnaei 

Wrightii 

scopulorum 

16    Urceolaria 

stenospora 

actinostoma 

usneoides 

chloroleuca 

Speerschneidera 

cinerea 

euploca 

scruposa 

Thelotrema 

17.   Usnea 

actinotuni 

angulata 

Auberianum 

barbata 

auratum 

a.  Florida 

catastictum 

c.   dasypoga 

Cubanum 

d.  plicata 

Domingense 

e.    articulata 

glaucescens 

cavernosa 

granulosum 

ceratina 

interpositum 

hirta 

lathraeum 

longissima 

latilabrum 

mollis 

leiostonium 

rubiginea 

lepadium 

strigosa 

lepadodes 

sulphurea 

leprocarpum 

trichodea 

219 


220 


VERRUCARIACE^. 


VII.  Verrucariaces 

1.  Dermatocarpon 

pusillum 
f.  Endocarpon 

arboreum 

cinereum 

fluviatile 

hepaticum 

Manitense 

miniatum 
complicatum 
fulvofuscum 
aquaticum 

Moulinsii 

Miihlenbergii 

ochroleucura 

pallidum 

pusillum 

rufescens 

tephroides 

Texanura 
3.  Pyrenula 

aggregata 

aspistea 

aurantiaca 

cinchonae 

fallaciosa 

fetivica 

geminella 

gemmata 

glabrata 

hyalospora 

lactea 

leucochlora 

leucoplaca 

mamillana 

nitida 


oblongata 

ochraceo-flava 

pachycheila 

punctiforrais 

quinque-septata 

rhyponta 

subcinerea 

subprostans 

thelaena 

thelomorpha 

tropica 

4-   Tri/pethelium 
aggregata 
catervarium 
cruentum 
Eleuteriae 
exocanthum 
Kunzei 

madrepiforme 
mastoideum 
megaspermum 
ochroleucum 
pallescens 
pyrenuloides 
scorites 
tropica 
uberinoides 
virens 

S    Verrucaria 

centhocarpa 

consequella 

dermoplaca 

epigaea 

fuscella 

glabrata 

margacea 

maura 


VERRUCARIACKiE. COLLEMACEA:. 


221 


microbola 

mucosa 

mnralis 

nigresccns 

papillosa 

pinguicola 

prospersella 

punctiforrais 

ruderella 

rupestris 

purpurascens 
Sprucei 
striatula 
tartaricola 
umbrina 
virens 
viridula 

VIII.  Collemacese 

1.   Col  I  e  ma 

aggregatum 

callebotris 

cladodes 

cocophorum 

crispum 

cristatellum 

cristatum 

cyrtaspis 

flaccidum 

furvum 

glaucophthalnium 

granosuin 

laciniatuni 

leptalt'um 

limosum 

melainum 

microphyllum 


microptychium 
multipartitum 
myriococcum 
nigrescens 

b.  leucopepla 
plicatile 
piilposum 
pustulatum 
pycnocarpum 
ryssoleum 
stellatum 
stenopliyllum 
ten  ax 
Texanum 
verruciforme 

2.  Hydrothyria 

venosa 

3.  Leptofjitnn 

adpressum 
apalachense 
bolacinum 
bullatum 
Burgessii 
caesiellum 
Californicum 
chloromelum 
a.  conchatum 
h.  stellaris 
corniculatum 
crenatcllum 
dactylinum 
dendriscum 
hypotracliinum 
iiiflexuni 
intricatulum 
juniperinum 
lacerum 


COLLEMACE^. PANNARIACE^E. 


marginellura 
minutissium 
palmatum 
phyllocarpum 
insidiosum 
macrocarpum 
pulchellum 
rivale 
sinuatum 
tenuissimum 
tremelloides 
4'  Mallotium 

albociliatum 
myochroum 
saturninum 

IX.  Pannariacese 

1.  Ephehe 

maramillosum 

Lesquereuxii 

pubescens 

solida 
f .  Heppia 

arenivaga 

Despreuxii 

Guepii 

polyspora 

virescens 
S.  Lecothecium 

corallinoides 

nigrum 

4.  Lichina 

confinis 

*  Willeyi 

pygmea 

5.  Nephromium^ 

articura 


cxpallidum 
Helveticuni 
leavigatum 
h.  parile 
Lusitanicum 
subleavigatum 
tomentosum 

6.  Omphalaria 

Cubana 

deusta 

Gerardi 

leptophylla 

lingulata 

phyllisca 

pulvinata 

pyrenoides 

symphorea 

Texana 

Wrightii 

7.  Polychidium 

muscicolum 

8.  Pannaria 

brunnea 

byssina 

carnosa 

crassophylla 

flabellosa 

glaucella 

grannatina 

Hookeri 

hypnorum 

lanuginosa 

lepidiota 

leucosticta 

lurida 

melamphylla 

microphylla 


PANNARIACE^:. 


223 


molybdaea 

b.  cronia 

c.  incisa 
nigrocincta 
pannosa 
Petersii 
pholidota 
placodopsis 
plumbea 
rubiginosa 

b.  conoplea 
Sonomensis 
stellata 
stenophylla 
symptychia 
tryptophylla 
9.  Pel  tiger  a 
aphthosa 
canina 

b.  spongiosa 

c.  membranacL'ii 
horizontalis 
malacea 
polydactyla 
pulverulenta 
rufescens 
scutata 

venosa 
10.  Psoroma 

hypnorum 
stellata 


11.  Solorina 

crocea 

saccata 

spongiosa 

12.  Sticta 

amplissima 

anthraspis 

aurata 

damaecornis 

dissecta 

erosa 

herbacea 

glomulifera 

pallida 

pulmonaria 
/'.  hypomela 
c.  linita 

13.  Stlctina 

crocata 

fuliginosa 

Hallii 

Huraboldtii 

limbata 

Oregana 

Pickeringi 

quercizans 

scrobiculata 

sylvatica 

tomentosa 

Wrightii 


GENERAL    INDEX. 


Acarospora,  152 

cervina, 152 

dealbata,  153 

privigna,  152 
Accessory  structures,  48 
Acharius,  1,  6 
Acids,  37 
-      action  of,  18 
Acoliuni,  85 

tigillare,  85 
Adaptations,  mutual,  53 
Aerial  alg£B,  33 
Affinity,  double,  33 
Affinity  of  lichens,  11 
Africa,  3,  19 
Agardh,  7 
Agassiz,  149 
Alaska,  20 
Alcohol,  24 
Alectoria,  165 

ochroleuca,  165 

sarmentosa,  165 
Algse,  25 
Algal  layer,  43 
Algeria,  19 
Alps,  149 
Altrnism,  31 
Altruistic,  18 
Analogy,  40 
Andes,  111 
Antberidia,  11 
Apr>thecia,  46 
Arabia,  3 


Arthonia,  128 
astroidea,  129 
atra,  131 
dispersa,  129 
glabrata, 130 
lecideellft>  130 
polymorpha,  130 
punctiformis,  130 
quintaria,  130 
radiata,  130 
tsediosa,  130 
varia,  131 

Arthothelium,  132 
spectabile,  132 

Artificial  key,  77 

Asci,  28 

Ascomycetes,  28 

Assimilation,  26 

Association,  31 

Autonomy,  14 

Bacidia,  109 

albescens, 109 
atrogrisea,  110 
chlorosticta,  109 
cuprea-rosella,  109 
iuundata,  110 
rubella.  110 
Schweinitzii,  110 
sufifusca,  110 

Bacteria,  26,  27 

BsBomyres,  87 
seruginosus,  89 


226 


GENERAL    INDEX. 


Baeomyces. 

byssoides,  89 

roseus,  88 
Baranetzky,  13 
Basidia,  28 
Basidospores,  28 
Beard-moBS,  23, 168 
Beer,  24,  168 
Bertram,  168 
Biatora,  105 

cinnabarina,  107 

contigua,  106 

dlapensisB,  106 

granulosa,  107 

myriocarpoides,  106 

parvifolia,  107 

peliaspis,  107 

russula,  107 

uliginosa,  106 

varians,  105 

vernalis,  107 
Biatorella,  104 

geophaiia,  104 
Biatorina,  104 

lutea.  104 

pineti,  105 
Bilimbia,  108 

hypnophila,  108 

mixta,  108 

sphaeroides,  108 
Bitter  principle,  20 
Blotting-paper,  66 
Bornet,  13,  187 
Brewing,  24 
Brittleness,  57 
Bryopogon,  166 

jubata,  166 

Oregana,  166 
Bucke,  101 
Buellia,  112 

badia,  114 

colludeus,  114 

coracina,  114 

dialyta,  113 

Elizae,  114 


Buellia. 

myriocarpa,  114 

Parmeliarum,113 

parasema,  113 

pulchella,  115 

Schaereri,  113 

spuria,  115 

stellulata,  114 
Buelliopsis,  112 

vernicoma,  112 

CaesHlpinus,  4 
Caliciacese,  81 
Calicium,  83 

Curtisii,  83 

f uscipes,  83 

byperellum,  83 

lenticulare,  83 

quercinum,  84 
Calkins,  144 
Camex'arius,  4 
Canada,  20 
Canary  Islands,  21 
Canary  rock-moss,  157 
Candelaria,  143 
Cape  Verde  Islands,  2^ 
Carbon  dioxide,  32 
Catillaria,  115 

grossa,  115 
Cave  dwellings,  19 
Celidiopsis,  112 

platycarpa, 112 
Centric,  40 
Cephalodia,  50 
Cetraria,  157 

ciliaris,  158 

cucullata,  159 

Fahlunensis,  158 

Islandica,  19,  159 

juniperina,  158 

lacunosa,  159 
Cbeese,  manufacture  of,  27 
Cbilblains,  161 
(Jbloropbyoeae,  34 
Chloropbyll,  26,  27 


GENKRAL    INDEX. 


227 


Chroolepus  umbriua,  34 
Cladonia,  92 

alclcoruis,  96 

aiuaurocraja,  100 

bellidiflora,  97 

cseapiticia,  94 

cariosa,  95 

ceuotea,  96 

cornucopioldes,  97 

cristatella,  95 

decorticata,  95 

deformis,  97 

delicata,  94 

digitata,  98 

timbriata,  98 

furcata,  99 

gracilis,  98 

lepidota,  96 

leporina,  100 

luacileuta,  95 

mitrula,  94 

papillaria,  93 

pulchella,  94 

pyxidata,  96 

rangiferiua,  19,  100 

squamosa,  99 

symphycarpa,  94 

turgida,  99 

micialis,  99 

verticillata,  98 
Cladoniacese,  87 
Classiticatiou,  73 

methoda  of,  75 
Cold,  36 

Collecting-box,  58 
Collection  of  lichens,  56 
Collema,  179 

crispum,  182 

cyrtaspis,  180 

tiacciduiu,  182 

laciuiatutu,  181 

leucopepla,  181 

limosum,  8 

myriococcuni,  181 

nigrescens, 181 


Collema. 

plicatile,  182 

pulposmu,  181 

pycnocaipuHj,  180 

ryssoleum,  181 
ColleraacesB,  179 
Color,  restoration  of,  63 
Couiocybe,  82 

furfuracea,  82 

pallida,  82 
Conotrema,  171 

urceolatum,  172 
Cousortism,  12 
Cora,  28 

Cortical  layer,  42 
Cortical  tissue,  47 
Crabbe,  100 
Crab's-eye  lichen,  150 
Crombie,  12 
Crottle,  150,  156 
Crystals,  acid,  43 
Cudbear,  22 
Cyanophyceai,  35 
Cyphelium,  84 

tubseforme,  84 

turbinatum,  84 
Jyphell*,  49,  196 
Cystococcus  bumicola,  34 

Dactylococcus,  35 
Darbishire,  14 
Dark  crottle,  156 
De  Bary,  12 
De  Candolle,  A.  P.,  6 
De  Notaris,  2 
Dermatocarpon,  17t 

pusillum,  177 
Dilleu,  5 
Dioecious,  187 
Dioscorides,  3,21,  23 
Disintegration  of  rock,  17 
Disk,  126 
Dog-lichen,  23 
Dropsy,  168 
Dryers,  66 


228 


GENERAL    INDEX. 


Dye,  21 
Dyeing,  20 

Earth-bread,  19 

Elepliautiasis,  20 

Endlicher,  7 

Endocarpon,  177 
arbox-eum,  178 
fluviatile,  178 
hepaticum,  178 
iniuiatuni,  178 

Evernia,  163 

f  urf  uracea,  3, 1()4 
vulpina,  22, 164 

Evolution,  39 

Ephebe,  186 

maniminosuru,  187 
pubescens,  186 
solida,  187 

Epidermis,  40 

Epilepsy,  23 

Eschweiler,  7 

Esenbeck,  Nees  von,  8 

Excrescences,  56 

Exine,  86 

Exosporium,  86 

Exodus,  19 

Ezekiel,  21 

Fabr ictus,  23 
Fairies,  156 
Fairy  rings,  49,  154 
False  lichens,  200 
Famintzin,  13 
Faveoli,  17 
Federigo,  21 
F6e,7 

Feld-elfln,  156 
Female  organs,  11 
Fermentation,  26 
Fevers,  23 
Food-substances,  26 

inorganic,  26 

organic,  27 
France,  22,  150 


Franklin,  20,  121 
Freezing,  36 
Fries,  7,  10 
Function,  loss  of,  27 

mechanical,  31 

of  lichens,  17 
Fungal  type,  40 
Fungi,  26 

spores  of,  37 

Generation,  spontaneous,  7,  9 
Georgi,  6 
Germany,  10 
Gessner,  3 
Glass,  23 

Gloeocapsa,  35, 189 
Glueing,  67 
Gonidia,  9,  11 
Graphidaceai,  124 
Graphis,  127 

dentritica,  127 

elegans,  127 

eulectra,  127 

scripta,  127 
Green  mould,  30 
Green  substance,  8 
Gyalecta,  117 

cupularis,  117 
Gyrostomum,  172 

scyphuliferum,  173 
Gyrophora,  119 

Dillenii,  122 

erosa,  121 

floculosa,  121 

hyperborea, 120 

Miihlenbergii,  121 

proboscidea,  120 

vellea,  121 

Hsematomma,  146 

ochrophjea,  147 

punicea,  147 

ventosa,  147 
Hair-powders,  23 
Haustoria,  41 


GENERAL    INDEX. 


229 


Huzslinskya  125, 
deniissa,  126 
gibberuloaa,  126 

Hedwig,  C 

Hemaus,  Mrs.,  97 

Heppia,  190 

adglutinata,  190 
Deapreuxii,  190 
urceolata,  19(» 

Herbarium,  65 

Heterocysts,35 

Heterotbecium,  116 

Himalayas,  111 

History,  1 

Horse-tail,  lichen,  166 

Hii^,  12,  52 

Humboldt,  168 

Hydrophobia,  23 

Hydrothyria,  183 
veuosa,  183 

Hypothallus,  133 

Hysterium,  34 

Icelaud,  20 
Icelaud  moss,  19,  159 
Iceland  scurvy,  20 
Idle  moss,  168 
Individualisni,  31 
Insects,  44 
Iodine  reaction,  19 
Ireland,  155 
Isidiuni,  200 
Isle  of  Man,  155 
Isolateral,  40 
Israelites,  19 
Italy,  3,  21 
Itzigsohn,  11 

Jaundice,  23,  159 
Jumelle,  13 

Key,  artificial,  77 

natural,  80 
Keys,  76 
Korber,  10 


Krempelhuber,  1 

Labelling,  69 
Lamarck,  7 
I^af,37,40 
Ijecanora,  148 

atra,  150 

Bockii,  149 

calcaria,  149 

cenisia,  151 

Cupressi,  149 

esculenta,  19 

Hageni,  149 

lacustris,  148 

muralis,  151 

orosthea, 148 

pallescens,  150 
«   pallida,  149 

r.ubina,  151 

subfusca,  150 

tartarea,  151 

varia,  149 
Lecidea,  110 

enteroleuca.  111 

geographicH,  111 

melancheima,  111 

panaeola,  111 
Lecideaceae,  102 
Lecothecium,  187 

corallinoides,  188 

nigrum,  188 
Ledges,  01 
Leighton,  12 
Lepra,  200 

viridis,  200 
Leptogium,  182 

chloromeluni,  183 
Lichen-alga?,  37 
Licheu-starch,  19,  37 
Lichen-tundra,  52 
Lichenes  im perfect  i,  2(X) 
Licheniu,  19»  37 
Lichenology,  history  oi,  1 
Lichens,  altltudinal  range,  62 

autonomy  of,  14 


230 


GENERAL    INDEX. 


Licbeus. 

cleauiug  of,  66 

collection  of,  56 

contiueutal  rauge  of,  202 

distribution  of,  52 

economic  value  of,  18 

false,  200 

function  of,  17 

latitudinal  range  of,  52 

list  of,  204 

morpbology  of,  39 

naming  of,  68 

occurrence  of,  52 

origin  of,  25,  29 

pbysiology  of,  39 

preservation  of,  65 

relation  to  algse,  33 

relation  to  fungi,  33 

sets  of,  65 

spores  of,  37 

study  of,  63 

uses  of,  16 
Licbina,  188 

confinis,  188 
Lindau,  14 
Liudley, 7 
Lindsay, 11 
Linn^,  5,  16,  124 
Litmus.  22 
Liverworts,  7 
Lopadium,  116 

pezizoideum,  117 
Lungs  of  oak,  199 
Lungwort,  199 

Male  organs,  11 
Mallotium,  184 

saturninum,  184 
Malpbigi,  4 
Manna,  19 
Massalonga,  10 
Mead,  Dr.,  23 
Medullary  layer,  43 
Medullary  tissue,  47 
Megalospora,  116 


Megalospora. 

sanguinaria,  116 
Metamorpbosis,  9 
Meyer,  2,  8 
Micbeli,  1,  4 
Microcosnios,  36 
Micrometer,  82 
Micron,  82 
Microscope,  9,  64 
Moisture,  62 
Monstrosities,  16 
Morison ,  4 
Morpbology,  39 
Mosses,  4,  5 
Mould,  26 

Mounting  sbeets,  67 
Mucor,  83 
Mudd,  10 
Mummies,  3 
Mycoporum,  131 

pycnocarpuni,  131 

Nageli,  11 
Natural  key,  80 
Neoformations,  50 
Nepbromium,  195 
Helveticum,  196 
Icevigatum,  195 
Lusitanicum,  196 
tomentosum,  196 
Nostoe  licbenoides,  35 
Nostoc  muscorura,  8 
Note-book,  62 
Nova  Zembla,  111 
Nux  vpmica,  23 
Nylander,  10,  52 

Okeu,  7 
Ompbalaria,  189 

umbella,  189 
Opegrapba,  126 

varia,  126 

vulgata, 126 
Orcbella-weed,  22 
Orcbill,  22 


GENERAL    INDEX. 


231 


Organs,  female,  11 

male,  11 
Orjcellarii,  21 
Orseille,  22,  150 

Pannaria,  191 

bruniiea,  192 

lepidota, 192 

leucosticta,  192 

luridum,  192 

molybdasa,  193 

rubigiuosa,  192 
Pannariaceae,  184 
Paper,  manufacture  of,  24 
Paraphyses,  47 
Parasitism,  12,  27 
Parchment,  161 
Parmelia,  153 

Borreri,  156 

conspersa,  154 

caperata,  155 

latissima,  157 

multisporum,  154 

olivacea,  155 

perforata,  157 

perlata,  157 

physodes,  155 

paxatilis,  156 

taeniata,  155 
Parmeliaceas,  144 
Parry,  101 
Paste-board,  24 
Patella,  29 
Peltigera,  193 

aphthosa,  50,  193 

canina,  23,  194 

polydactyla,  191 
Perfumes,  24,  101 
Pertnsaria,  174 

communis,  176 

globnlaris,  175 

gloiiierulata,  176 

leioploca,  175 

iiuiltipuncta,  175 

pustulata,  175 


Pertusaria, 

velata, 176 
Phylogenesis.  32 
Phylogeny,  36 
Physcia,  138 

adglutinata,  139 

aquila,  140 

caesia,  139 

ciliaris,  141 

comosa,  141 

hispida, 141 

hypoleuca,  140 

obscura,  139 

parietina,  23 

pulverulenta, 140 

setosa,  139 

speciosa,  141 

stellaris,  140 

tribacea, 140 
Physciacese,  132 
Physiology,  39 
Pilophoron,  89 

cereolus,  89 
Placodium,  135 

aurautiacum,  136 

cerinum,  136 

cinnabarinum,  136 

citrinum,  136 

elegans,  137 

ferrugineum,  136 

murorura,  136 
Pleurococcus  vulgaris,  35 
Plinius,  3,  21 
Pockets,  68 
Podetium,  46,  92 
Poisoning,  22 
Poly-ancestry,  32 
Polycoccus  punctiformis,  35 
Polyps,  6 
Polychidium,  189 

muscicohim,  100 
Porcher,  121 
Potatoes,  20 
Powders,  liair,  101 
Preservation  of  lichens,  65 


232 


GENERAL    INDEX. 


Priestley,  green  substance  of, 
Primal  substance,  8 
Propagation,  vegetative,  9 
Propagative  organs,  49 
Protococcus  vulgaris,  8 
Prototype,  32 
Pseudo-lichens,  200 
Psora,  118 

atro-rufa,  119 

decipieus,  119 

icteria,  118 

rufonigra,  119 

Rusellii,  11§ 
Psoroma,  191 

hypnorum,  191 

stellata,  191 
Puff-balls,  26 
Pulveraria,  200 
Pustules,  178 
Pycnidla,  51 
Pyrenoid  bodies,  35 
Pyrenotliea,  200 
Pyrenula,  170 

aepistea,  171 

nitida,  171 
Pyxine,  137 

cocoes,  138 

picta,  138 

sorediata,  138 

Quinine,  substitute  for,  23 

Rabies,  23 
Ramalina,  160 

calicarlB,  160 

ceruchis,  161 

homalea,  161 

miuuscula,  160 

polymorpha,  161 

reticulata,  162 

rigida,  162 
Range,  continental,  60, 
Red  cup  moss,  97 
Red  pepper,  23 
Reicheubach,  7 


Reindeer  moss,  20,  101 
Reiuke,  2, 12, 13    ' 
Rejuvenescence,  49 
Rhizoids,  44 

aerial,  44 
Rinodina,  133 

Bishoffii,  134 

chrysomelsena,  135 

constans,  134 

oreina, 134 

sophodes,  134 

turfacea, 135 
Rivularia  nitida,  35 
Rocella,  3,  21,  162 

leucophfea,  163 

tinctoria,  163 
Rock,  disintegration  of,  17 
Rock-hair,  166 
Rock -moss,  122 
Rock -tripe,  20 
Roman  empire,  21 
Roots,  44 
Rucellai,  21 
Rucellarii,  21 
Ruellius,  3 
Rust,  26 

Sac-fungi,  28 
Sanders,  24 
Saprophytes,  28,  29 
Saussure,  149 
Schweudener,  2,  11 
Scrap-book,  68 
Scrofula,  168 
Scurvy,  20 
Scytonema,  190 
Shakespeare,  168 
Sirosiphon,35,  186 
Snails,  43 
Solomon,  3 
Solorina,  194 

crocea, 195 

saccata, 195 
Soralia,  14,  107 
Soralium,  49 


GKNERAL    INDEX. 


233 


Soredia,  6,  37,  48 
Soredium,  49 
Speerschneidera,  153 

euploca,  153 
SpermagODia,  6,  11,  50,  loc. 
Spermatia,  10,  51 
Spermatozoa,  11 
Sphaerophorus,  86 
fragilis,  86 
globiferus,  86 
Spilonema,  200 
Spore-characters,  10 
Spore-sac.  28,  47 
Spores,  28 
Sprengel,  7 
Stahl,  12 
Stane-raw,  156 
Staney-rag,  156 
Starch, 19 
Sten-laf ,  156 
Stereocaulou,  90 
condensatum,  90 
coralloides,  91 
denudatum,  91 
paschale,  91 
ramulosum,  91 
Sterigmata,  51 
Sticta,  49,  197 

ampllssima,  198 
Oregana,  50 
pulmonaria,  198 
Stictina,  49,  196 
quercizaus,  197 
tomentosa,  197 
Stitzeuberger,  10 
Stone-crottles,  155 
Study  of  lichens,  63 
Sturgis,  12 
Substance,  primal,  8 
Substrata,  53 
Sweden,  20 
Switzerland,  10 
Symbionts,  31 
Symbiosis,  12 

antagonistic,  31 


Symbiosis. 

mutualistic,  31 
Systems,  73 

artificial,  73 

natural,  73 

Tanning,  24,  27 
Tartars,  19 
Tartary, 19 
Thalline  type,  47 
Thallophytes,  39 
Thallus,  39 
crustose,  40 
foliose,  40 
fruticose,  40 
secondary,  92 
vertical,  92 
Thamnolia,  lu2 

vermicularis,  102 
Thecae,  47 
Thecium,  47 
Thekes,  47 
Theloschistes,  142 

chrysophthalmus,  143 
concolor,  142 
flavicans,  143 
leucomela,  144 
lychneus,  142 
parietiuus,  143 
polycarpus,  142 
Thelotrema,  172 

lepadinum,  172 
Theophrastus,  1,  3,  4,  21 
Toad-stools,  26,  88 
Tournefort,  1 
Tree-hair,  166 
Tree-moss,  168 
Tripe  de  roche,  121 
Trypethelium,  170 

vireus,  170 
Tiickerman,  12 
Tulasne,  11 
Type,  crustose,  47 
foliose,  52 
fruticose,  44 


234 


GENERAL    INDEX. 


Type. 

fungal,  46 
thalline,  47 

Ulf-mossa,  22,  164 

Umbilicaria,  20,  123 
papulosa,  123 
Pennsylvanica,  124 
pustulata,  124 

"Umbilicus,  44 

Units,  morphological,  6 

Urceolaria,  145 

actinostoma,  146 
scruposa,  146 

Usnea,  3,  167 

barbata,  23,  168 
linearis,  167 
longissima,  168 

Variolaria,  200 

Vasculum,  58 

Velvet-moss,  122 

Verrucaria,  173 
fuscella,  174 
margacea,  174 


Verrucaria. 
muralis,  174 
nigrescens,  174 
pyrenophora,  174 
rupestris,  174 

Verrucariacefe,  169 

Vesuvius,  92 

Virey,22 

Voigt,  7 

Wallroth,  2,  8 
Weather-side,  60 
Weber,  1 

Whooping-cougb,  23,  168 
Willey, 

Wolf's-moss,  22,  164 
Woroniu,  13 

Xylographa,  128 

opegraphilla,  128 
parallel!  a,  128 

York,  duke  of,  23 

Zambia,  111 


PLATES   AND   DESCRIPTIONS 


PLATE  I. 

Algal  Types. 

1.  Ci/stococciis  (Protococcus).     The  individual   cells   are   sur- 

rounded   by   terminal    branches   of   hyphae   known   as 
haustorio. 

2.  Chroolepus.     The  branching  chain  of  cells  is  enclosed  by 

haustorial  hyphse. 

3.  Nostoc.     The  chains  are  intermingled  with  hyphas,  which 

form  no  haustoria.    The  larger  cells  in  the  chains  are 
known  as  heteroci/sts. 

4.  Gloeocapsa.    The  cells  are  small,  enclosed  by  a  thick  strati- 

fied gelatinous   covering  which  is   penetrated  by   the 
haustorial  branches. 
6.  Rivularia.    Algae  and  hyphae.    In  Nostoc  as  well  as  in  Rivu- 
laria  the  individual  chains  are  enclosed  by  a  gelatinous 
substance. 

6.  PobjcoccHS.     Cells  form   colonies   which   are   enclosed  by 

haustorial  hyphae. 

7.  Dactijlococcus.    The  cells  are  elliptical. 

8.  Pleurococcus.    The  cells  are  irregular  in  outline  and  en- 

closed by  a  dense  hyphal  structure. 

9.  Sirosiphon.    This  is  a  branching  many-celled  alga.     The 

figure  represents  a  terminal  branch.     Hyphae  are  not 
shown. 


GUIDE    TO    LICHENS      Schneider, 


plate  I 


ALGAL    TYPES. 


PLATE   II. 
Lichen-types. 

Crustose  forms : 

1.  Calicium  hypereUum. 

2.  Graphis  scripta. 

3.  Rhwdina  oreina. 

Foliose  forms : 

4.  Endocarpon  miniattim. 

5.  Collema  nigrescens. 

6.  Sticta  puhnonarla. 

Fruticose  forms. 

7.  Cetraria  Islandica. 

8.  Rocella  tinctoria. 

9.  Usnea  harhata. 

1,  2  and  3  are  about  natural  size.  4  to  9  inclusive  are  some 
what  reduced.  6,  7  and  9  represent  only  portions  of 
plants. 


GUIDE    TO    LICHENS      Schneider. 


Plate    II. 


LICHEX-TVPES. 


PLATE  III. 

Histology  of  a  Foliose  Lichen. 

{Sticta  amplissinia.) 

\.  Vertical  section  through  apothecium  : 

a,  b,  thecium,  consisting  of  the  spore-sacs  and  para- 
physes ;  o,  colored  ends  of  paraphyses ;  c,  d,  hypothe- 
cium  ;  c,  upper  hyphal  layer;  d,  lower  cortical  layer;  e, 
upper  algal  layer;  /j  medullary  layer;  g,  lower  algal 
layer;  h,  cortical  layer;  /,  rhizoids  (aerial). 

2.  Vertical  section  through  thallus: 

a,  epidermal  layer  ;  b,  upper  cortical  layer ;  r,  algal  layer; 
d,  medullary  layer  ;  e,  lower  cortical  layer;  /,  rhizoids. 

3.  Paraphyses  and  spore-sac  more  highly  magnified. 

4.  Spores  highly  magnified. 

5.  Algae  {Protococcus}  and  haustoria. 

1  and  2  magnified  about  300  diameters  ;  3, 4  and  5  more  highly 
magnified. 


GUIDE    TO    LICHENS      Schneider 


Plate    III 


HISTOLOGY  OF  A    FOLIOS E   L/CHEiV. 
{Sticta  amflissima.) 


PLATE    lY. 
Apothecial  axd  Thalline  Types. 

Apothecial  types  : 

1.  Fungal  type  of  apothecium  as  it  occurs  in  the  (^ali- 

ciaeese.. 

2.  Fungal  type  of  apotheciuni  as  it  occurs  in  tlie  Cla- 

doniaceae  and  some  Lecideaceae. 
8.  Fungal  type  of  apotheciuni  as  it  occurs  in  the  major- 
ity of  Lecideaceae. 

4.  Thalline  type  of  apotheciuni  as  it  occurs  in  the  Phys- 

ciaceae  and  Parmeliacea?. 

5.  Immersed  type  of  apotheciura  as  it  occurs  in  Endo- 

carpoti  and  other  genera. 
Thalline  types  : 

6.  Crustose  thallus. 

7.  Crustose  thallus  with  upper  cortical  layer. 

8.  Foliose  thallus  without  upper  cortical  la^'^er. 
i>.  Foliose  thallus  with  both  cortical  layers. 

10.  Fruticose  thallus  as  in  Stereocauhn. 

11.  Fruticose  thallus  as  in  Cladonia. 

12.  Fruticose  thallus  as  in  Usnea. 

All  the  figures  are  diagramatic  ;  1  to  9  inclusive  represent  ver- 
tical sections;  10,  11  and  12,  longitudinal  sections. 


GUIDE    TO    LICHENS.     Schneider. 


Plat*    IV. 


AFOTHECIAL    AXD    JHALLLVE    TYPES. 


PLATE   Y. 
Generic  Spore-tyfks. 

1.  Acarospora. 

2.  Acolium. 
8.  Alectoria. 

4.  Arthonia. 

5.  Arthothelium. 

6.  Bacidia. 

7.  Baeomyces. 

8.  Biatora. 

9.  Biatorella. 

10.  Biatorina. 

11.  Bilimbia. 

12.  Bryopogon. 


GUIDE    TO    LICHENS.     Schneider. 


Plate.  V. 


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SPORES. 


PLATE  VI. 

Generic  Spore-types  (con.). 

13.  Buellia. 

14.  Buelliopsis. 

15.  Caliciura. 

16.  Catillaria. 

17.  Celidiopsis. 

18.  Cetraria. 

19.  Cladonia. 

20.  Collema 

21.  Coniocybe. 

22.  Conotrema. 
28.  Cyphelium. 

24.  Dermatocarpon. 


GUIDE    TO    LICHEWS      Sfht»«fdfr 


Plate    \'\. 


Jl 


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Jl 


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JS 


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o 


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STORES, 


PLATE   VII. 
Generic  Spore-types  (con.)- 

25.  Endocarpon. 

26.  Ephebe. 

27.  Evernia. 

28.  Graphis. 

29.  Gyalecta. 

30.  Gyrophora. 

31.  Gyrostomum. 

32.  Haematomma. 

33.  Hazslinskya. 

34.  Heppia. 

35.  Hydrothyria. 

36.  Lecanora. 


GUIDE    TO    LICHENS.     Schneider. 


Plale  VII. 


iP 


Z5 


^ 


Z6 


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27 


ZS 


0  ^ 


M 


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JJ 


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55 


Jo 


SPORES. 


PLATE   VIII. 

Generic  Spore-types  (con.). 

37.  Lecidea. 

38.  Lecothecium. 

39.  Leptogium. 

40.  Lichina. 

41.  Lopadium. 

42.  Mallotiuin. 

43.  Megalospora. 

44.  Mycoporum. 

45.  Nephromium. 

46.  Omphalaria. 

47.  Opegrapha. 

48.  Pannaria. 


GUIDE    TO    LfrHENS.     Schneider.. 


Flatc  Vin 


S  FOXES. 


PLATE  IX. 

Generic  Spore-types  (con.)= 

49.  Parmelia. 

50.  Peltigera. 

51.  Pertusaria. 
62.  Physcia. 
5.3.  Pilophoron. 

54.  Placodium. 

55.  Polychidiuni. 

56.  Psora. 
57!  Psoroma. 

58.  Pyrenula. 

59.  Pyxine. 

60.  Ramalina. 


GUIDE    TO    LICHENS      Schneider. 


Plate    rX 


SPOKES. 


PLATE  X. 

Generic  Spore-types  (con.). 

61.  Rinodina. 

62.  Rocella. 

63.  Solorina. 

64.  Speerschneidera. 
66.  Sphaerophorus. 

66.  Stereocaulon. 

67.  Sticta. 

68.  Stictina. 

69.  Theloschistes. 

70.  Thelotrema. 

71.  Trypethelium. 

72.  Umbilicaria. 


GUIDE    TO    LICHENS      Sahn^ider 


PJatt    X. 


SPORES. 


PLATE  XI. 
Generic  Spore-types  (con.). 

73.  Urceolaria. 

74.  Usnea. 

75.  Verrucaria. 

76.  Xylographa. 


GUIDE    TO    LICHENS.     Schneider 


PUte  XI. 


73 

^0 

^ 

JM. 

SPORES. 


